A Basic Guide To Graphics Cards

A Basic Guide To Graphics Cards

Graphics cards are gaining in importance. While gamers were always very clear about the benefits of a decent graphics card, other PC users innocently believed in what Intel told them. That they don't need anything other than the graphics chipset that was embedded in the motherboard.


But Vista changed it. It pushed people towards discrete graphics cards as some decent GFX horsepower was required to enable all the bling-bling that Microsoft put in its latest OS. After Vista came this thing called HD content. Playing HD content too requires some decent graphics power. Nowadays, we have some decent IGP solutions based on Nvidia's 9300 chipset or AMD's 780G chipset, but even they are sometimes not sufficient enough to pull off the HD content with ease.

And then of course, there is the need to game. An urge to kick some alien at a beautiful tropical island in all its glory. If you lust for the scenes like those in Crysis, owning a decently powerful graphics card almost becomes a necessity for you.

Once you are sure that you need a graphics card, comes the question - which one is suitable for you. And here I hope this basic guide will come handy to many visitors here, specially those who are looking to buy their first graphics card. (I will be dealing with PCI-E cards unless specified)

What's in name?






For someone looking to get his first graphics card, the naming scheme from both Nvidia as well as ATI/AMD can be, in almost all circumstances, the easiest way of determining the relative strength and power of a graphics card.

As far as numbers are concerned, (note the emphasis) IN A SERIES OF CARDS lower number means less powerful card even if IT HAS MORE MEMORY/GPU SPEED/FEATURES. This is true for both Nvidia and ATI/AMD. 

An example will be:


9500GT < 9600GT < 9800GT
HD3650 < HD3850 < HD3870

Now you have to keep in mind that the comparison is valid only if all cards belong to one particular series. So you can't say 9500 GT > 8800 GT even though later has a lower number. Similarly, on AMD side you can't say HD4650 > HD3870

AFTER NUMBERS come affixes and suffixes. This is more true for Nvidia now as AMD, since HD 3XXX series, has done away with them. But because AMD's older cards still carry the suffixes, we will have a look at them too. 



But first Nvidia:


GTX > GTS > GT > GSO > GS



Caution: This is the scenario by and large, but recent name changing spree by Nvidia made things a little confusing so it may not always be true. An example will be 8800GT > 8800 GTS (320MB). But it is expected that once 9XXX and 8XXX series fade out of the market, with 2XX and subsequent series 



Nvidia's will have:


GTX = High End

GTS = Performance

GT = Mainstream

GS = Budget

G = Entry level


On AMD side things are no longer that confusing, as only numbers remain in the names. But for older cards this was the hierarchy structure:


XTX > XT > GT > Pro

Apart from that there were certain special cards like Radeon X1800XL and Radeon X1800 GTO but their naming scheme was temporary in nature.








Memory is the key thing....

After the name, the second thing we look for in a graphics card is how much memory it has. In fact, many does not even look for the name and directly step on to the memory matters. This, if you have read about the naming scheme, is a bad practice.

Graphics cards come with different memory configurations. 128 MB is the lowest memory that you will get with a graphics card currently while maximum amount goes up to whopping 2GB. Nowadays, different cards carry different type of memory and it would not hurt us to know more about them. 




DDR2:This is the type of memory which you will get on the entry-level graphics card. It's nothing but just a high-speed version of DDR2 that goes into the normal memory slots in a motherboard. DDR2 is cheap, in fact very cheap, and board makers often slap ridiculous amount of it on the budget cards. For example you can even buy a 8400GS with 2GB DDR2 memory. But unfortunately, it won't make it run faster. Also,please note that there is nothing called GDDR2. if you see, GDDR2 on some box or sticker, you can be sure that it has been put their either because of misprint or to fool consumers.

DDR3: A lot better than DDR2. Primarily because of the fact that it was developed by ATI for graphics cards and its real name is GDDR3. In fact, unlike what is the case with DDR2, DDR3 in a graphics card is not similar to your usual DDR3 desktop memory. GDDR3 is still used by both AMD/ATI and Nvidia on their performance/high-end cards. Now, important thing to note is that if you have choice between two cards with DDR2 and DDR3 memory, always go for DDR3 one. Even if the amount of memory available on card with GDDR3 is less. An example will be 8600 GT with 256 MB GDDR3 and 8600GT with 1GB DDR2. In this case, 8600GT with GDDR3 will be faster than 8600GT with DDR2 even if it has less memory.


GDDR4: First used by ATI on HD 3870, it's a marginal improvement on GDDR3. While it provided a boost in speed as well as lowered the power consumption, it wasn't much and Nvidia did not even attempt to use it on its cards. The problem was that GDDR4 also increased latencies and this coupled with higher prices, spelled end for GDDR4 even before it could properly take off. Nowadays you can get GDDR4 on 4670 from Sapphire. But it comes at a premium that (still) doesn't justify the purchase.


GDDR5: Top stuff nowadays. As HD 4870 shows, GDDR5 brings a massive increase in bandwidth available to GPUs. Significantly faster than GDDR3 or GDDR4 even with increased latencies. Expected to be as ubiquitous as GDDR3 by end of this year.


Point 1: If everything else is same, it's always better to get the card which has faster memory. If possible always chose card with GDDR3 over DDR2 because the performance difference could be substantial.Point 2: More memory helps in high-resolution Anti-Aliasing as well as in games which have lots of texture like Fallout 3. So if everything else is same (including type of memory), chose a card that has more memory.

 
Video Playback

As stated earlier, apart from rendering game graphics and driving display on monitor, graphics card also play a very important role in high definition content playback.

If you require a card for your HTPC needs, here is what you need keep in mind:


Connectors available:Almost all graphics card available in the market can provide dual-link DVI, HDMI and VGA connections. 



For HTPC-minded folks, HDMI is the most important bit and while most cards provide HDMI through a DVI-to-HDMI connector, it's not tough to find a card that has native HDMI connector.

Codec support:While AMD/ATI uses Avivo (UVD 2.2), Nvidia uses PureVideo to provide hardware acceleration for video playback. Both engines can decode most HD content without breaking sweat, but tests have revealed that AMD/ATI's UVD has better support for VC-1 content.


Note: While choosing a card for HTPC needs, it's always advisable to go for a card with passive cooling. Computing requirements for HTPC needs are not that huge and even entry-level cards like HD 3450 which are often paired with passive cooling solutions can easily handle them.

As an added bonus, HD 4XXX series can also pass 8 channel LPCM audio output over HDMI while Nvidia's cards need to use S/PDIF for same functions. (Ironically, 8 channel LPCM audio output over HDMI is available with Nvidia IGPs beginning from 8XXX chipsets.)










Support With monitor

Graphics card is not the end in itself. It's just a component inside the PC which also has a processor, RAM, PSU and other equipment. The overall performance of a computer depends not on the graphics card but on all the components and how well they complement each other. So, it is important to keep in mind your other hardware, while deciding on a graphics card.

Here is what you need to keep in mind:
Monitor: The deciding factor and thats very important.. You need to see what is the native resolution of your monitor and chose graphics card accordingly. You may have Rs 20K to spare, but it's a folly to buy GTX260 for a 15" monitor with a resolution of 1024 X 768.

While, a lot depends on what kind of games you play, right now I will put it like this (for gamers who like to play games at native resolution of their monitor with everything set to high):


15" monitor (1024X768) = Pair it with a GFX card worth 5K or less17" monitor (1280x960/1440X900) = GFX card worth 5K to 7K19" monitor (1440X900) = GFX card worth 7K to 9K22" monitor (1680X1050) = GFX card worth 9K to 13K24" monitor (1920X1080) = GFX card worth 13K to 20K




PSU:Second most important aspect while choosing a graphics card. A graphics card is the most power-hungry component in a PC nowadays and it is very important that you should know how capable your PSU is before deciding on a GFX card.

Again, I will give a rough estimate:


GFX card without 6-pin PCIe connector (less than 75W) = Any international brand PSU with at least 300W (like something from Seasonic) or any well-known 400W PSU like those from VIP Silver/Gold series.

GFX card with one 6-pin PCIe connector (maximum power draw 150W) = Any international brand PSU with at least 350W (like those from Seasonic) or decent PSUs with above 450W likes CM 460W extreme power plus.

GFX card with two 6-pin connectors (maximum power draw 225W) = A solid PSU with at least 450W like the one from Corsair. Preferably, a very good PSU with more than 500W. And no, 600W extreme power from cooler master won't do. To understand why read this.

GFX card with one 6-pin and one 8-pin connector (maximum power draw 300W) = Any good SOLID PSU with 550W or more like Real Power 550W.Multi-GPU cards like 4850 X2/4870X2: At minimum a very good 650 PSU like TX 650 from Corsair. A good stable PSU with over 700W preferred.


CPU: Also a factor while you decide on a graphics card. A less powerful CPU will not be able to feed the more graphics card with enough data and result in sub-optimal performance. This is why pairing a HD 4870 X2 with an E7200 is not really a very good idea. Always try to get a card with which your CPU can keep up.