• Competitor rules

    Please remember that any mention of competitors, hinting at competitors or offering to provide details of competitors will result in an account suspension. The full rules can be found under the 'Terms and Rules' link in the bottom right corner of your screen. Just don't mention competitors in any way, shape or form and you'll be OK.

4890 overclocking

Associate
Joined
4 Aug 2008
Posts
1,778
Location
Waterlooville
Ive started to OC my 4890, ive got Rivatuner working from a fix on the Guru3D forum, im not sure how acturate the temp readings are from it, hense my question.

The Core and mem temps are pretty safe around 80 each under heavy load, however the VRM temps are 120deg c

Is this normal/safe if not what can i do to fix this

Currently got it clocked at 930/1100
 
hi,

ok bit the bullet and raised the settings to those suggested i.e. 950 by 1100

the test failed so lowered it to 900 by 1050 that worked first time

not a big jump i thought so wasnt expecting much when i ran 3dmark06

bit sirprised even that small increase had taken my score from 12600 to 13090 :D

almost a 400 point increase

i was worried the fan might start making a lot of noise but it just stayed the same below the noise of the cpu fan and power supply fan which are also really quiet so well chuffed :)

any ideas on why it wasn't happy with 950 i'd be interested as i've seen somebody around here getting it up to 1000 :eek:

best regards
Ian
 
mines up a lot higher now but i am notching the volts up slightly too

kusanagi: what i mean by reseated is that i unscrewed the large read heatsink and reapplied thermal compound and cleaned the old stuff off .
 
I may as well ask here, but is it safe to underclock cards? I presume it is of course, but my options in Windows are vcore, engine (GPU) and memory.

The defaults are 1.312V, 850MHz and 4900MHz by default. Can I just zip down the engine and memory to their minimums (700MHz and 3000MHz) without touching the vcore?
 
You can, but why would you want to?

I flashed my bios to idle at .93V....but why would you want to decrease the 3d clocks?
 
I may as well ask here, but is it safe to underclock cards? I presume it is of course, but my options in Windows are vcore, engine (GPU) and memory.

The defaults are 1.312V, 850MHz and 4900MHz by default. Can I just zip down the engine and memory to their minimums (700MHz and 3000MHz) without touching the vcore?

The card should automatically drop to clocks far lower than that in 2d mode.
 
hi,

i was sort of following this but i'm a bit puzzled by the setting of the mem clock at 3000 or 4000 when the software only lets you overclock the GPU to 1000 and the MEM Clock to 1200

in fact my overclocking screen seems to be argueing with itself as it says my GPU clock has been raised by me to 900 and yet in the box at the bottom which tells you what your running at it says 240 meg

is there some multiplier going on i dont know about or is there something wrong as i would have thought these figures would have been the same ?

Ian
 
The figure at the bottom is your current 2D clock speed. The settings you enter in CCC only take effect when you run a 3D application.

As for the memory clock, GDDR5 runs on a 4x multiplier, so 1000MHz in the CCC = 4GHz memory speed.
 
The card should automatically drop to clocks far lower than that in 2d mode.

Yeah if you are talking about 2d clocks it already does this for you...

How do I know it's doing it? I fire the "Smart Doctor" up and ATI's software and the readings it shows are still at the figures above, they don't seem to lowering. Nor anywhere within the software does it even mention dropping into 2-d mode. Would installing Rivatuner be a good idea?

You can, but why would you want to?

I flashed my bios to idle at .93V....but why would you want to decrease the 3d clocks?

Sorry, I forgot to mention outside of games.
 
Last edited:
oh crap,

so running at a mem speed of 1050 thats actually 4200 :eek:

just as well i asked that question thanx HeX for being so informative ( and quick lol )

just one other thing are these settings dependant on each other ?
what i mean is i increased both gpu anbd mem by around 5%
can you increase one more than the othere and if so what are the effects ?

Ian
 
ok from wondering around looking at peoples sig's it doesnt look as though there is a link between how high you push the gpu and how high you push the mem

so if you get to the position where you can only push one slightly more than the other which should it be ?

Ian
 
Back
Top Bottom