Fundamental GPU Questions

[jahk888]

I am currently looking to purchase a GPU to finish off my pc build.
I have a fundamental question about graphics cards so please excuse my ignorance.

While browsing I notice four key areas listed:

1.) Core MHz
2.) Memory
3.) Stream Processors
4.) Shader Clock

As an example I would like to compare the following two MSI Geforce GTX 770 cards:

http://www.overclockers.co.uk/showproduct.php?prodid=GX-208-MS&groupid=701&catid=1914

http://www.overclockers.co.uk/showproduct.php?prodid=GX-201-MS&groupid=701&catid=1914

These items are the same price and even look the same bar the colour scheme however the only differences I can spot is that the first link has double the Memory but slightly less Shader Clock and slightly less Core MHz.

My question is the following: What do these four items mean in PLAIN english. What is better, having more memory but less MHz overall or more Core MHz but less memory? As a side note, which graphics card out of the two I have listed would be the more powerfull?

 

[Orcvader]

1) Core clock means nothing to be honest, with the way GPUs work, it's better to have more shaders/cores/whatever else they're called as it's the parallel performance that's usually important.

2) Depends on the resolution and the game you're playing. On 1080p, 2gb will do you fine with most games, but if you start playing more demanding games, a bigger resolution, or even Eyefinity/Surround vision, then more memory will help.

3) See 1).

4) Nvidia has different parts of their GPUs running at different speed, and the shaders run at a higher speed so it doesn't bottleneck the rest of the GPU.

And yet, even then, you can't really use any of these specs to compare different GPU models due to architecture differences, the only true way to compare GPUs is looking at reviews .

And to answer your question, it depends on the resolution you plan to play on. Personally, I would say get the 4gb version, the clock speed difference is very small and you'll probably be able to easily overclock it to the faster card's speed.

 

[Havana_UK]

Generally speaking the faster the core the better, and the more memory the better, however choosing the right card depends on your circumstances and requirements.

For example, gaming at 1080p rarely requires more than 2GB of VRAM for current (and likely the near future) titles, however if you're going to be gaming at 1440p (or higher) or multi-screen setups then you may need more VRAM, but even today 2GB is often sufficient.

As for the two cards you linked to the Lightning is a special version that (I believe) has extra power features, different BIOS and a few other tweaks to drive performance far higher than that which a standard GTX770 delivers. The Lightning versions are aimed at the enthusiast segment of the market where users are looking for extreme levels of overclocking potential, not your average Joe.

I should add that while I've said more MHz is better, as pointed out above you can't read that statistic in isolation as it's meaningless. For example, a GTX770 at ~1GHz or so generally delivers superior performance to the HD7970 at 1.1GHz (or maybe higher), but there are some situations where the HD7970 will outperform the GTX770.

 

[jahk888]

Thanks for the replies, it seems the stats can point you in the right direction but each card is different in terms of overall performance and potential!