Why 7800's scale badly...and how to improve

[maverik-sg1]

I have found through many hours of benching these babies and now playing with volt modded units that they really are CPU limited.

However there is a way to ensure that the cards scale better overclocked than some reviews would have you believe.

I found out that 2d has to scale up with 3d to see some better improvements (especially in 01) - I ran 2d at 555 and 3d at 600mhz to achieve my 47499 in 3dm01.

Thats where the reviews fail in that respect - the 2d in most cards (all of them AFAIK) is set to 1.2v which limits 2d clocks to around 400 (at best), but to get a true appreciation of how fast these cards go, the 2d and 3d have to be fully overclocked - and to get ethe best out of the benchmarks u really need to mod the BIOS to give the 2d and throttled 3d 1.4v.

This will enable you to run 530mhz on 3d and 500+ on the 2d - of course you dont need thewm to run this fast in games (especially SLI) but to maximise the benchmarks - thats what you gotta do.

Cheers

The Coach

 

[nick25]

Nice find mate.

 

[Alanore]

The 7800 is a weird creature, its has so many diffrent clocks, and sections of the chip running at diffrent speed. And the thing with the no linear performance from the ROPs jumping multiplier.

It would be nice is Nvidia released some informantion on how the whole thing operates, only then will you be able to get the most out of it.

 

[maverik-sg1]

It would be nice if Nvidia released some information on how the whole thing operates, only then will you be able to get the most out of it.

Too true mate, until then it's trial and error.

 

[Blow]

I have found through many hours of benching these babies and now playing with volt modded units that they really are CPU limited.

However there is a way to ensure that the cards scale better overclocked than some reviews would have you believe.

I found out that 2d has to scale up with 3d to see some better improvements (especially in 01) - I ran 2d at 555 and 3d at 600mhz to achieve my 47499 in 3dm01.

Thats where the reviews fail in that respect - the 2d in most cards (all of them AFAIK) is set to 1.2v which limits 2d clocks to around 400 (at best), but to get a true appreciation of how fast these cards go, the 2d and 3d have to be fully overclocked - and to get ethe best out of the benchmarks u really need to mod the BIOS to give the 2d and throttled 3d 1.4v.

This will enable you to run 530mhz on 3d and 500+ on the 2d - of course you dont need thewm to run this fast in games (especially SLI) but to maximise the benchmarks - thats what you gotta do.

Cheers

The Coach

NICE WORK MATE

Could you tell me how to get the 1.2v to 1.4v ?

 

[GoLLuM4444]

NICE WORK MATE

Could you tell me how to get the 1.2v to 1.4v ?

http://www.malvescorner.net/7800.html

That's the hardmod - I'd get shigs to do it for you if you're clumsy or using a big soldering iron like I was when I sent mine to him.

To change 2d to 1.4v change it in the bios with nibitor then flash it on with nvflash.