Why we need a NAS (file server) at home

The modern home is digital and networked. More and more devices or their supporting set-top-boxes/peripherals are getting connected to the Internet as well as each other for sharing data such as music, pictures, videos, etc. What started with just the PC/Laptop having this connectivity has invaded smartphones, tablets, TV or TV set-top boxes, surveillance cameras, camcorders, digital cameras, etc. Maybe the future will involve white goods too (refrigerator, microwave, etc). 

They key point is in this digital and connected world, devices have their own content (generated or consumed) in digital format  like

1. videos is growing to astronomical sizes. 1080p is easily in access of 10 GB per movie. We have our consumer digicams and camcorder generating this data at home which we wouild like to backup as well as surveillance data
2. music which is encoded as lossy with MP3 codec now has a better option of FLAC which does not compromise fidelity (of the source from here it is made) but would take up much larger space than MP3. 
3. Data of gaming consoles, smartphones and other handheld devices
4. And of-course our PC and laptops have data which needs a backup (application installers, our generated data)

And we need storage do maintain these library. Tons (or rather terabytes) of it. .

Whether you buy all this electronic content, or download pirated variants, or just say exchange with friends, their is a cost (in terms of the pain) to re-download it incase we lose it. I have 30$/month broadband connection in India which can move a 4 GB per day from the cloud to my network, till the Fair Usage Policy (FUP) kicks in after 25 GB and throttles my broadband speed to just 128 Kbps. Besides you may not get the content also (like some old videos or photographs you recorded).  Their may be  need to talk and explain that why you want to download again. You need reliable fail-safe storage.

So how do we handle this ? Two ways actually:

1. the first is to tie storage to access devices (smartphones, tabs, Pcs, Music streamers, HTPCs etc)_ and always keep a copy on centralized non-RAID storage. You have to manage  downloading from cloud, moving from download device to access device and moving it to backup device. And it may not be possible to automate this always. Also the access device has storage constraints  what if it gets full and we can't expand storage. 
2. The other option is to use an *extensible* centralized storage (aka NAS) which can support multiple access protocols (NFS, CIFS, Apple, DLNA, etc), concurrent clients and a high speed wired+wireless router which can help access devices pick up this content on demand from the NAS. In essence my own personal cloud. 

I chose the 2nd option. I like the idea of separation of storage, compute and access devices simplu\y because I can upgrade the parts as and when they reach obsolescence.

Let me list down the requirements for this NAS

(1) The storage cost should be cheap (its mostly write once read many type). HDDs fit the bill.

(2)  The storage should be durable (we need RAID support)

(3) The storage should be able grow with the need -- I need a big chassis which can atleast support 4 (or more  HDDs) even though I may begin with 2 or 4 only

(4) Should support High transfer rates (read/write) preferably near the limits of Gigabit Ethernet and primarily because I am possibly going to access data concurrently (for eg., TV playing videos while PC copying some data into the NAS)

(5) Its big or its beautiful is a nice to have feature, but not a mandatory requirement

(6) Consume less power if possible, though being the most energy efficient is not a mandatory requirement

(7) Hot-swap is a nice to have feature, not mandatory

In India pre-built BYOD NASs with high performance cost about $300 for a 2 bay, $600+ for a 4 bay and upwards of $2000 for 8-bay and 12-16 bays cost upwards of $4000. Since I am looking immediately at a 2-bay and 4-bay in 1 year time, I am staring at an investment of $600+ and the struggle to get it and we still have to pay atleast $200 per TB of RAID storage. That's an immediate investment of $1000. Very high for a file-server.

So I decide to make my own. Here's what I think I need:

(1) Software -- FreeNAS 9+ (BSD based, but who cares if it works well and can support my hardware)

(2) Chassis -- A Tower or NAS chassis with 6-8 bays atleast (later I can chuck it and go for a tall tower case if I need more disks)

(3) Motherboard -- Preferably no onboard sound card, no on board graphics or just the most simple integrated graphics, the maximum number of SATA ports supporting RAID or a RAID add on card with good number of ports. The RAID port is a very key requirement. Also one PCI express slot to add expansion RAID card could be useful in long-term \.

(4) RAM - As much as freeNAS needs, Its cheao these days or 8 or 16 or 32 isn't going to scare me off.

(5) HDDs -- Low cost/GB, Low speed (I do not think HDD speed is a bottleneck but rather than the GbE interface to data transfer) which means low power also and safe to be used in RAID setup ( wI will use only software RAID for the ease of repair if I lose the hardware and can't find the similar RAID controller card or on-board chipset)

With this in mind I go about this build. keep tuned in the following posts for what build I did.

One Disk or Many Disks

I am slicker for speed, stability and reliability (maybe because i work professionally in the telecom domain). And then comes cost (which I am also conscious about, but not the cost of the above three). Possibly adaptability. In reality, even  assembling a PC has some of these tradeoffs provided you are aware and make this choices and not go by the wind. My use-case is a dual boot Windows + Linux box (love to do hackintosh, but I have a macbook already and to believe the apple's integration works much better). One area foremost for its applicability is storage. Lets see how.

(1) Performance - I must use SSD for OS and applications, while HDD for dynamic application and OS data, and just another data. With SSD i can get high performance, but not high storage capacity and heavy write reliability at practical (even if its expensive prices). With HDD I can get the latter two, but not the best in class performance(even with RAID).

Since we want provision of apps and reasonable amount of SSD space to be left for GC to be invoked infrequently, I did not think a 64 GB SSD would b enough. Next I wanted the speed king for this. OCZ Vertex 4 was one, but its 64 GB speed of I/O was less.

For linux I had done a opensuse 12.1 install on my old 160 GB caviar green and it seemed to allow a maximum root partition of 20 Gb out of which 33% was free after full install of client 7 server packages and quite a few addons. So I guessed since /home will have to be on HDD, and most linux apps are not as big as Windows, a 30 GB would be more than enough. I settled for Corsair Nova, though it might be among the slowest of SSDs around, still atleast twice as fast as an HDD.

(2) Reliability -- I must achieve reasonable isolation between OSes and see that the impact of failure is eliminated at the particular OS itself, so that rules out a single disk with multiple OS. So i definitely need multiple SSD and either multiple disks for data or RAID for one shared data disk. One more thing is that I consider SSDs to be more reliable than HDD, if they are not frequently written to.

I wanted my disks to ber big & fast (ruled out the Velociraptors and neither were they available in local market). So 7200 RPM, 64 MB cache, SATA 3 gbps was on the menu. Caviar blacks and WDE4 were the choices. However the former is unsuitable for RAID and so the choice fell on the enterprise drives.

(3) Adaptability -- a Tuning of one OS must not impact other in anyway and it should be tunable independently in terms of storage. So I can't do multi-boot OS config on one disk. Definitely not on the OS, but maybe on the data as re sizing and moving partitions would be simpler.

Cost Comparison (in India)
(a) General approach -- a 2 TB disk = 250$
(b) Reliable generalized approach -- 2x2 TB disks (2 x 300$) = $600 in India
(c) Fast but not entirely unreliable approach -- 1x128 GB SSD for Windows ($230) + 1x30 GB SSD for Linux ($60) + 1 TB data disk ($140) = $430
(d) Fast & Reliable
         (i) 1x128 GB SSD for Windows ($230) + 1x30 GB SSD for Linux ($60) + 2 X 1 TB data disk in RAID mode ($280) = $570
         (ii) 1x128 GB SSD for Windows ($230) + 1x30 GB SSD for Linux ($60) + 4 X 500 GB data disk in RAID mode ($90x4=$360) = $650

So if you put cost before everything else and is your only criteria go for (1). if you want speed but no reliability go for (c) If you want performance first, reliability second & adaptability third go for the choices in (d). And of-course the more disks you use you may run into constraints of PSU and number of SATA ports on your motherboard. 

Personally I started with (c) and plan to move to (d)(i) in due course of time to spread the cost. I can't put two many disks right now beacuse I have 8 SATA on my motherboard which are used like

(1) One for Optical DVD Drive
(2) One for HAF-X chassis front eSATA
(3) Two for Hot-swappable bays of HAF-X

That takes away half of the ports, and my expansion needs are one blue-ray writer (am yet to see a combo BLUE-ray/DVD/CD writer & reader). If I go for (d)(ii), I need to accomodate 2 SSDs and 4 HDDs requiring 6 SAta ports and I have just 4 left. Have a strong feeling that motherboard manufacturers should increase the number of SATA ports in high-end mobos to atleast 12 and preferably 16 (its a lot and I am not stacking up Internet porn). Going forward i see myself probably losing front eSATA or one hot swappable bay.

PC is fun and challenging if you do it my insane way. I definitely say throw your laptop and pick a tab + PC with tab for laid back content viewing & presentation and the PC for all content creation needs.

Cable Management for my PC

Along similar lines of my previous posts an air-cooling is the subject of cable management. I work in Telecommunications area and we building networking and communicate software. And do that we use networked computers and boards in our labs. And we do our cable management by grouping them, tying them up and then running them neatly behind the equipment avoiding man made catastrophes ( I can remember the anguish when I run 24 hour or 48 hours long duration performance tests to test software stability, only to find out that it failed in closing stages because a network cable either on equipment under test or network pulled out because someone accidently tripped or walked over some cables).  The use case of such arrangement is that it is easy to debug in case something goes wrong or carry out the upgrades when they are needed. And without getting lost or pulling 10 other things just  to fix one. The same holds good for the PC as well.

However cable management for PC has another angle. If you do not have a mish-mash or noodle soup of cables in your chassis next to and over the motherboard, you:

(1)    Allow air to freely circulate and cool the hardware

(2)    Prevent micro dust from  collecting on the cables and spoiling their look

Most people however do not pay attention to this as they had no perceivable value in the short-term. Its the similar attitude summarized by martin Fowler in his keynote address at AGILE CONFERENCE 2011, "the software works for me as a user and hence why do I care about how the inside (design) looks !!! What matters is that it is cheap and that enough". Unfortunately like software design, cable management effects the stamina of hardware (how long it lasts).

Here is how the insides of my PC look like. Quite a few extension cards (graphics, sound, WiFi, case lighting slot plates, etc) as well as multiple fans, peripherals, case mod lights etc (not exactly a simple setup but not the most complex one either):

Not the best cable management that you may come across (and I have an story to hide at the back of the motherboard. More on this later), but decent enough to begin with. My chassis is a HAF-X and it provides very decent cable management options such as:

(a)    Rubber grommets to allow cables to go out from the PSU and come in at the right place back leaving the least obstruction.
(b)   A nice enclosure next to the PSU to hide the cables coming out from my PSU

(c)    Slightly elevated case panel at the back of the motherboard to accommodate cable bundle

(d)   And enough placeholders for typing the cables and running them in organized manner at the back with zip  ties or even twist ties

Besides I have a Corsair AX850 *fully* modular PSU, which allows me to just connect the cables to the PSU which are really needed, eliminating the un-needed cable bundle.  I recommend others to use modular units or semi-modular with fixed Motherboard power connectors (you anyways need them always). This Corsair  PSU has very neat cables which have a surrounding piping.

Assemblers need to pay attention to the cable management options on their chassis when they buy them, incase they are not buying the HAF-X ;-)). The only gripes I have about my installation are:

(a)    Because of the case height the optional power cable on the top just about reaches the header on the motherboard. Not good as it will put some lateral force on the header. Don’t know whom to blame CM for the height of the recess or Corsair for the length of the cable

(b)   The Placement of PCI-X Power cable son the Graphics card (Asus GTX 560 Ti) is on the top longitudinal side which requires bringing them out through the VGA fan bracket. Its an ugly arrangement. I prefer such connector to be  shorter side which would face the front of the case (see how its done in my Asus Xonar Essence ST soundcard with 4-pin molex power connector at the shorter side) making the cable length that is required to be inside the chassis very small and non obtrusive. This would have become more ugly if I had more than 1 Graphics card in SLI mode. Why Asus why  ?

(c)    And I also wonder sometimes that if cables are supposed to be run mostly on the side behind the motherboard, why do manufacturer’s don’t run DVD and Blue ray drive’s power connectors and data cable connectors on the side. It would be much cleaner (look at the way the HDD’s and SSDs have been mounted in the HAF-X).  At-least they should give an option in some models …

Occasionally when I am able to steal some time on the weekend from my family, I do open the PC up and  tidy up the cable management even more. I still have the back of the motherboard side to address …

Installing the right type and number of chassis fans

One consideration while buying a case is to decide as to what type of fans will come installed, how many and just in the case has no fans pre-installed by default, or we want to replace the default ones or provision for extension then what fans should one put and what would be the orientation.

I own a HAF-X (HAF stands for High Air Flow or something like that) which is probably one of the best air cooled cases that one can get on the market. It is big in itself, Has provision of 5 fans, air vents, dust filters and even a VGA bracket with optional fan (which I have added). Sounds an overkill. Maybe.

IMO, what is needed is minimally in a case is

(1) One Fan which will pull cool air into the case
(2) One Fan which will exhaust hot air away from the case (the air becomes out because the electronic components conduct heat to the flowing air which regulates their temperature)

This is simple theory, and IMO most users need just these two fans. Nothing more, nothing less. And I say this even though I own the HAF-X ( I am sure the others are not so effective)

The fans must exhibit some qualitative characteristics.

(a) They must be sized to fit the provision in the case
(b) They must be able to move lots of air
(c) They must do (b) while not making too much noise that it disturbs users. Its like a Motorbike/car silencer, the absence of which is either hated or loved.
(d) They must not overload the current drain capacity of the motherboard

Unfortunately what most vendors and retailers propagandize *prominently* is size (which is right), LED color,  type of bearings, lifetime, blade structure, fan speed, wattage in their feature list and bury the air pressure and capacity (CFM, H2O pressure level), Noise level (dB), current drain in their specification sheet. 

The voltage in the motherboard rail is fixed at 12V. And each fan connector on the motherboard has current drain capacity, which must not be exceeded. Before connecting any chassis (or CPU fan) to the motherboard, care should be taken that the current drain does not exceed this limit, otherwise you can burn the motherboard.

If the airflow capacity (expressed in cubic feet per minute or CFM) is low, the cooling will be less, irrespective of what RPM the fan spins at.  And by the way bigger fans have to spin slower & make less noise to move more air which is a strong case for their installation. Big is beautiful.

If the chassis fan (which has 3-pin motherboard connector or a 4-pin Molex connector to connect to PSU/Fan-Controller, and spins at constant speed) makes a lot of noise, it will create some disturbance for users (the level varies with tolerance). If total noise of all fans is above 50 dB its quite audible to me and anything about 70 dB bothers me for instance. IMO fan controllers which control their speed by reducing voltage, solve the noise issue, but MAY impact the cooling ability of the case, which is the primary purpose of the chassis fans in the first place.

Usually High CFM/RPM and Noise/Size are opposing factors and a tradeoff is made in each fan to my observation. You may not be able to get the best of everything like (highest CFM + lowest Noise + smallest size + lowest rpm) in one fan.

And finally if you want to add a dice of color and lighting to your case, you can add LED fans instead of plane jane ones. But only after you got the other basics right.

The need and pitfalls of RAM Cooler installations

The concept of air cooling can be extended from a CPU to other components in the motherboard like RAM, PCI/PCI Express cards, etc. You need a heatsink and a fan to dissipate heat. You can see this in a graphic card also.

The RAM modules are an important target. From my C programming background, I understand the best way to speed up any routine or algorithm is to try and make it CPU bound (eliminate frequent memory lookups) and also achieve some locality of space and time of both data and instructions (in  other words make full use of CPU's cache memory). This is a low-level programming craft and most applications in my domain are written in high level languages like C/C++ , where developers are ignorant of this, or do it only for some key routines and not whole critical path code (forget the whole code). Worse many believe that design optimizations give better results and therefore no need to do low level code tuning. 

RESULT: A lot of memory accesses in any code(application). With multi-threaded applications and the gap between CPU speed and DRAM speed, this means very frequent DRAM access translating into heat buildup in the DIMM modules.

My Gskill RipJaws X had heatsink fins. So i extended the CPU cooler concept by looking at a RAM cooler fan and I got one from Gskill in Turbulence II with lovely blue LED fans. Corsair and Patriot also make  this cooler.  Easy to mount and dismount and takes power from a molex cable which can be connected to the PSU. However there are two things I want to warn others about

1. One side of the Turbulence II touches the Fan on the CPU air cooler since the DIMM slots are next to the CPU on my motherboard (Asus P8Z68-V PRO/GEN3). I see most Mobos have this arrangement. So it will block block some airflow into the cooler. And I had to shift the DIMM cooler towards one side to make sure it fit. That's where the second problem started

2. The base of the RAM Cooler's holders fits on the white DIMM slot levers (which we pull down to eject DIMMs). When I shifted the RAM cooler it covered the USB 3.0 header on my motherboard for the front USB 3.0 slots in HAF-X. Since I did not have a USB 3.0 device as of today, I disconnected the front USB 3.0 header as of now. It is the only open issue and I cannot find a way out except take a plier and alter the RAM cooler's holder

So my general opinion is that the co-operation between Motherboard manufactures, Air cooler makers and DIMM makers need to increase and they need to define some dimension, spacing and layout guidelines which will make CPU coolers, DIMMs and RAM coolers more compatible with each other. If I need a USB 3.0 front port any time in future, I have no option but to remove this Gskill RAM cooler or install one from Corsair (which I suspect may fit based on the pictures of it) or just use my trusty plier.

As a general rule, now I feel that whatever we mount on the Mobo (except normal sized PCI/PCIe cards), must be done outside the case at the time of purchase to check compatibility or have a return policy

CPU Cooler Installation Blues

The CPU cooler, Coolermaster Hyper 212 EVO, which i use in my PC had in itself a fair amount of challenges, one of which was because of some bad packaging and which effected only me,  while other challenges can be faced by others. Let me list them down into two broad categories

(1) Installation of the Cooler (aluminum radiator part)
(2) Installation of fans

Issue 1
Before deciding to buy a cooler I noticed that my HAF-X case had a backplate cutout which as per the manuals and videos shown by Coolermaster is used for quickly installing the heatsink even with the motherboard already mounted in the case. The cabinet is so good in so many areas that we hardly expect any issue. The Hyper 212 EVO like most other heatsinks requires a backplate to be installed. Unfortunately the HAF-X's backplate cutout is small and partially covers the backplate screw holes making it impossible to mount the cooler with the motherboard in the cabinet. What a let down !!! This is a manufacturing defect in HAF-X, but not a very high severity one as a general users hardly changes coolers often.

Issue 2
I had to take out the motherboard (since I was doing it for the first time, it was a nuisance, risk and trouble) and then mount the heatsink on top of it. And mounted Wait. Now I couldn't get the retention plate fixed as the screws will not fit in the backplate holder. After going over the manual with a magnifying lens ;-)) and watching some installation videos, I figured out that something was wrong with my retention plate. I had to remove the Motherboard again, remove the back plate, repackage the whole cooler and together with the motherboard take it to the vendor (Ankit Infotech)  from whom i bought my components. The guys at the vendor's shop were a little clueless and ran around to call some technician who was equally dumbfounded. The owner then decided to replace my unit and took out another Hyper 212 EVO piece. We opened it to check and whoa !!! This time the retention plate will fit because the non removable screws are proper. We swap the retention plate.

I was finally able to install this big heatsink with the motherboard mounted and using a dot method of thermal paste application.

The next problem domain is the fan installation. Some questions/issues which I had

(1) How many fans to install ? One (was supplied) or two (one on each side) ?
(2) Should we use 4 pin fans or 3 pin fans in case I want an LED Fan and not the plane jane fan that comes with this heatsink
(3) what should be the mounting orientation of fans i.e push air into heatsink or pull air out of heatsink ?
(4) Will the facing the DIMM slots obstruct them or get obstructed by installed DIMMs ?


And here is what I concluded by practical experimentation and wisdom of others on the Internet

(1) Two is better than 1. The heatsink picks up and spreads heat from CPU and we need to dissipate it quickly so that temperature can be controlled.
(2) I have an Asus P8Z68-V PRO/GEN3 motherboard. It has two 4 pin PWM fan connectors for the heatsinks while all other power and chases fan connectors are 3 pin. 3pin fans cannot be speed controlled by motherboard and spin at their max speed. The idea is that the case airflow is fixed and therefore all chassis fans can be 3 pin while CPU cooler fans can be controlled  to match the load on CPU (which lowers noise). I decided to go for 2 new matching Xtraflow LED fans (red) and not use the one suppled with the cooler. Costed me Rs. 1000/-  extra.
(3) In HAF-X there is a huge 230mm fan at front (lower side), grilled vents in drive bays and a 200mm fan at one side for cool air intake. The fan at the back and the two fans on the top are for exhausting warm air. To match this orientation, the heatsink fan facing the intake fan was made a push fan (i..e it pushes air into the heatsink) while the other side facing the exhaust was made a pull (pulls warm air out). This way their is are no opposing air currents created by fans
(4) Yes they do. I have 4 x 4 GB GSkill Ripjaws X DIMMs and the fan facing the DIMMs does touch (but just marginally) the DIMM closest to it which means the fan has to sit half a mm protruding from the heatsink. I was lucky that the fan just touched the DIMM on three counts. First the thickness of the heatsink was just right (many top-end heatsinks will be wider and will surely block one of the DIMM slots on my motherboard).  Secondly the spacing between the CPU and DIMMs was just about right. And thirdly, the height of the heatsink fins on my DIMM modules was also just right. I have heard that the fins on the Corsairs are taller which would have made mounting this fan a big problem. This is Issue No. 3 and a potential deal breaker.

So I think we can judge what needs to be taken care while buying & installing an after-market CPU cooler of air cooling type. I might summarize this by some key guidelines

(a) Buy the Cooler, DIMMs and motherboard together and install them at the vendors place, otherwise have a return agreement with suitable swap option. I have not seen many internet reviews pointing to such problems/questions that I faced especially with the installations and I expect many users to encounter atleast one of them.
(b) Buy Fans with 3-pin connectors for chassis and 4-pin (PWM fans) for the CPU cooler. If you do not like the sound made by chassis fans whirring at full speed, then go for a 5.25" fan controller (NZXT, Lian Li, etc make them) and connect the chassis fan to it and not the Mobo. Just leave CPU fan connected to the Mobo and let it to its own power management. I prefer you mount two fans.
(c) Mount the cooler on the CPU and Motherboard before fixing the motherboard in the chassis. Don't depend on the cutouts. You will save time and trouble.
(d) If you buy a RAM with tall heatsinks, either leave the last slot empty or maker sure you buy a tall CPU cooler and a case to accommodate that ;-)). The HAF-X is a tall and wide one, but others are not and you may just run up into a situation where the case side panel is being blocked from getting closed because of the heatsink or fan.

Their are so many failure points in this, but hell it works well after all this hungama !!!

The importance of a CPU Cooler

Many folks who buy assembled or for that matter bought branded PCs tend to overlook the importance of one key factor in the craft of PC building,  which is to take care of heat dissipation. I read about this after going through some newegg videos and could immediately correlate to the ideas as I have worked for a telecommunication equipment manufacturer (though on the software side) working with Compact PCI and ATCA chasis with tightly packed computing boards and loud whirring fans. And we know how big a killer heat is. Of computer equipment that is. 

Most friends who I approached for advice for assembling a new PC had the stock coolers supplied with the Intel/AMD CPUs they had. The shopkeeper who sold me the computer parts (and assembled it) in Bangalore's Computer Street (S.P. Road) possibly did not think that a separate add on cooler was a required or mandatory part and made no recommendation. A stock cooler is the norm.

But i had other ideas based on my experience. That's why I bought one of the best air cooled Chassis on the market, the Coolermaster HAF-X in the first place. Big guy with a lot of big & small fans to move air. And I came back after the initial build for a CPU Air Cooler and bought the Coolermaster Hyper 212 EVO (which is an entry level budget  air cooler to my reading & assessment) after failing to get the V6 GT locally or online in India. Did a DIY installation with manual and web videos help and mounted two 120 mm PWM LED fans (more about this later):

I will sell you some numbers to highlight the value of this device to my computer.

Stock cooler: Idle Temps of 42-44 deg. centigrade, Full load Temps of 100 deg. (with Prime 95 torture test with 99% CPU usage on all 4 cores of my Core i7-2600K CPU)

CM Hyper 212 Evo: Idle Temps of 34-36 deg. centigrade, Full load Temps of 60-63 deg (sustained at this level even with a 8 hour run)

A good 5-6 degrees on idle and 40 degrees on loading.

The ambient temperature in the room was around 30 degree centigrade. I felt some throttling by the CPU in the former case at full load and that's how it was holding on to a temperature of 100 degrees.  And all this with a budget aftermarket air cooler. The high end CPU coolers from Noctua (like the NH-D14) when combined the famed Artic Silver 5 thermal paste (i used the one from Coolermaster that came with the cooler) are reported to run 15-20 degrees cooler at full load and possibly just a few degrees cooler than what the Hyper 212 gave me at idle state.

If you think that we are going to do even a moderate 50% loading of CPU, you can guess how much the CPU cooler can help. That said if you are going to use a computer just for browsing, downloading, watching streaming videos, blogging, uploading some content, you will do fine with the stock cooler that come with a CPU. Just don't buy an i7 then. Settle for a dual core i3 with lower clock speeds.

To my judgement, therefore, an air cooler is a must for a workstation (that's my use case) or a server (where you can expect higher loads continuously). And if you are a gamer (who's going to potentially overclock also), you should open your purse and go for a high end cooler (100$+ range with two fans). For a thinner installation, I think the CM Hyper 212 (just a shade above Rs. 2000/- in India) is a VFM addition (read insurance) which will help in prolonging the usable life of the CPU.

More on cooler installation in the subsequent posts