Which would be better to overclock VRAM or GPU for gaining performance boost?

Question

I have an AMD Radeon HD7750 Saphire 1GB GDDR5 Edition which is getting pretty outdated and I don't have enough money to get another video card.

To solve this I started OC-ing it using CCC.

The thing is I don't know which would give me more performance boost: OC-ing the GPU or VRAM ?

Solution 1

I don't know which would give me more performance boost: OC-ing the GPU or VRAM ?

Both and neither. It depends on the game, the monitor (resolutions) and the settings you use.

The actual GPU is a 'Cape Verde' chip. It is the hearth which does your calculations. If it is not fast enough for your game but the memory is more than fast enough then overclocking it will help. Probably even lineair. (That is a 10% OC might yield 10% performance gain).

On the other edge the CPU might be fast enough but spent most of its time waiting for memory. (E.g. when playing UHD or 4K with 8x antialiassing). In that case ramping up CPU speed will not help much, but increasing bandwidth to the memory will.

And lastly, there are many situations which fall in between these two, and they are not mutually exclusive. As a result it is usually best to OC both.

There are ofc exceptions. Some cards are sold with a weak GPU chip and lots of slow memory (which usually does not make any sense on an average performance scale, but people tend to buy graphics cards with as much memory as possible in the vague but false idea that this 'also must be the fast cards'.

The HD7750 is not one of those. It had a fast memory hungry GPU and proper GDDR5 (fast!) memory. Thrust the GPU team (aka AMD) to have done its research on this and boost both to keep that balance.

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Side note 1: If you play real time games then turning down the resolution might help a lot to smoothen the screen. E.g. say your native resolution is 2560x1440. Set the game to only 1280x720. That way the card has to do only ¼^th of the calculations.

Side note 2: Keep an eye on power consumption. Make sure that your PSU can handle the extra +12v needed before you OC. Ditto cooling.

Solution 2

In my experience, overclocking the GPU clock yields higher performance gains with the tradeoff that there is usually a very limited amount of headroom to push the GPU clock, particularly if your graphics card already has a factory overclock. Being a Sapphire graphics card, I'd assume that this is the case as most vendors will overclock the reference design.

You can overclock the VRAM as well and usually you can 'push' the VRAM rates further than the clock rates, although the performance yields aren't as great.

Generally, it is best to try and optimise both settings. My personal preference is to try and push the VRAM as much as possible and once I have found the limit for that, to then try and push the GPU clock.

So the answer to your questions is: overclock both for the maximum performance! If you only want to overclock one setting, my experience is that overclocking the GPU clock gives the highest perfomance gain (versus overclocking the VRAM).

As a side note, I have found overclocking to be safe as long as you use safe increments and continually test using a suitable benchmark. It is generally best to Google your particular graphics card to see what other users have been able to achieve and then use these results as an estimate to your overclocking ranges. Keep in mind that due to tolerances/random factors in the manufacturing process that your graphics card may overperform or underperform relative to other cards... but I find this the joy of overclocking, to see if you are 'lucky' and have got yourself an overperforming graphics card.

Comments

[TermoZour]

My PSU is 500W so it would do good. As for what game, I'm playing GTA V now with settings at normal but water quality at very high. When I'm increasing the texture quality then it starts lagging. Would OC-ing my memory help here ? Also GTA is using 1200 out of 1024 VRAM and is running at 1028x720. When checked in Control Panel it said I have something like 5Gigs of VRAM. How is that ?