Which parameter have bigger impact when we OC a video card: Core or Mem?

[Franklogus]

Hi all!

I am intending to overclock my back-up PC video card (It?s a MSI 9800 PRO). Perhaps, in next months, I will can to buy a better one, but, for the time being, would be good if I could to extract, from it, some more boost?

I have read about video card OC in some forums, and I decided to try ATI Tool (V. 0.24), in order to find the ?limits? of Core & Mem of my vc.

As an information, the default speed of my MSI 9800PRO is:

Core = 380 ; Memory = 340 (680)

After running this utility, I got it :

Max Core (No Artifacts) = 450 [with DEFAULT Mem]
Max Mem (No Artifacts) = 402 [with DEFAULT Core]

Well, I know that, if I increase the Core speed, I will not can to reach that ?Max Mem?, and vice versa, because when we raise the two parameters together, they push the vc a lot! And, as this 9800PRO do not have temp sensor, I cannot control its temps, what is not good.

So, the big question is: which parameter should have (at least, in theory), the better impact to FPS? Knowing that:

1) I am an occasional gamer, never play for many hours.

2) I ONLY play racing simulators, as, for instance, GT Legends, FIA GTR, Live for Speed and Richard Burns Rally.

3) I got used to apply the following eye-candies: 4xAA & 8xAF

4) I do not intend to buy some better cooler solution for my MSI 9800PRO; its stock heatsink is huge and it is good, according to some reviews.

5) I want to make a safe OC, not going to the real ?limit?.

If I will know which of these 02 parameters could give me some better results, I could push more it than the other, to have a good final result.

PS: Sorry, I am a newbie concerning to OC, but, should I to use the option Scan for Artifacts ONLY after that I define these 02 parameters? right? Is there some danger of damage, using this option, if I set, for example, the parameters as Core = 430 & Mem = 370 (740)?. What do this program make when, in this specific option (Scan for artifacts), it find some of them? Does it manage to decrease some (or all) of these parameters, until that it reach the stability?

Well, that?s it? Thanks in advance for any help / tip!

 

[BlueWeasel]

ATI Tool does a decent job of determining the maximum mem and core values, but just use those values as a guide. 450Mhz core is a huge overclock on a 9800 Pro and you'd likely get lockups and/or artifacts if you tried to run it that high.

Your best performance is going to come by raising both values, not either one or the other.

I'd set the overclock to 9800XT values (412 core, 370 mem), and go from there. There is little chance that you'd damage the card permanently at those speeds. You'll probably be able to push them further, though, so play your favorite game for 10-15minutes and see if it's stable. If so, push both values up +5Mhz until you start seeing artifacts. Back off 5-10Mhz from the overclocks that give you artifacts, and those would be the maximum overclocked values to use. If you see artifacts after extended playing periods, then lower the overclocked values until the card is completely stable.

 

[nJett]

In my experience core speed tends to be more important for FPS but I imagine it varies depending on the game. If you are replacing the video card soon I wouldn't be too worried about OCing it very high - they are usually pretty hard to kill (at least in my experience), I've cooked a few over the years and they all came back fine after safer clock speeds were restored. The trick is to not leave them on if they are overheating - usually stories about people cooking their video cards to death are because they didn't power down the computer quick enough after the card started to overheat.

 

[Franklogus]

Thanks for your opinions, buddies!

After some tests, I got a Core = 420 and Mem = 382, very stable. Using Scan for Artifacts options, of ATI Tools, 422 & 385 give one artifact after 25 minutes, so I decrease the slide a little, and tested for 02 hours, playing games, the settings above...

Not that huge, but a decent overclock: 10,5% to Core, and 12,35% to Mem...

But, sincerely, I was hoping for some better final result, because my video card is that MSI 9800PRO with the green PCB = R360 Core(XT), "underclocked" by MSI (Bios of 9800PRO) for "pressure" of ATI... So, comparing to 9800XT, the OC was almost insignificant: 2% to Core, and 4,6% to Mem...

Anyway, as I was playing with default speeds so far, the "gain" is not so negligible, right?

Thanks a lot for your attention with me!