4870x2 running rather slow...

[plowman]

Hi all,

Just got a shiny new Sapphire 4870x2 and i'm having some problems.

Namely, it won't run at its standard GPU and Memory clock speeds, which should be 750 and 900 respectively. It runs at 507 and 500.

I understand it does this for 2d work, but even when i'm running FSX and I have GPU-Z updating live in the background, these slower speeds won't budge.

Any advice?

[dark shader]

maybe you have too less performance on your PSU, so that your 4870X2 dont get enough power.....

[KarmaKiller]

Could you post your system specs, including your power supply info?
Also, make sure you have the latest drivers off of ATI's site. Not the manufactures site.
Also check for a update on your chipset drivers. And may look to see if there is a BIOS update available too.

[plowman]

Thanks for replies. System specs:

CPU: Intel Core 2 Duo E6850 @ stock
Mobo: Gigabyte GA-G33M-DS2R
RAM: 6GB DDR2 800Mhz - Crucial Ballistix
Graphics: Sapphire ATi Radeon HD 4870X2
PSU: Enermax Liberty 620W

I'm downloading now.

[plowman]

Ok I now have the most recent display drivers and I already had the most recent chipset drivers. No improvement, though.

Well actually, the first GPU now runs at 750Mhz, but the mem still at 500. No change in the second GPU - still 507/500.

EDIT: Sorry my mistake, there is no change at all - the first GPU ran at 750 before driver update...

[KarmaKiller]

Hmm..
I'm wondering if the GPU doesn't have some kind of power saving mode, when it's not under load.
The only thing I would know to do is check it while it's under load.(playing a game)
I know rivatuner has a option to have a little read out in the corner of FPS, and core/mem clocks too. But I don't remember how to set that up.
But I would say check it in a game, and see what the clock values show then.

[plowman]

Yeah that's what I've been doing - setting FSX to play in a window, whilst veiwing GPU-Z in the corner, which updates itself. Do you think it could be my PSU (620W) as on the Sapphire site it says it requires a 650W? I didn't think 30W would make a difference, seeing as I only have 1 HDD, 1 ODD, and a few fans...

[KarmaKiller]

Well, I don't wanna tell you no, it's not your PSU and then be wrong.
But at the same time, enermax is a very good brand of PSU's, and most of the time manufactures take in to account cheap PSU's. So IMO, I would find it hard to believe that it is your PSU.
But it never hurts to test another PSU, see what happens.

Did you check for a BIOS update?

[2monsters]

What does ccc report the clocks at?

[plowman]

ok - it seems that the cores and the memory DO crank up to the correct speeds but only when the games are in full screen mode, lol.

Ive just come out of full screen and they are now both at 507/500. weird.

Thanks for your help KarmaKiller.

[zulquar]

what are the 12 v rails on ur psu ... and 620 w is not enough for hd 4870 x2 i think :\ ..... anyway the 12 v rails will justify that i think u need about 45 amp :| dont remember for a single hd 4870 u just need 32 amps

[plowman]

what are the 12 v rails on ur psu ... and 620 w is not enough for hd 4870 x2 i think :\ ..... anyway the 12 v rails will justify that i think u need about 45 amp :| dont remember for a single hd 4870 u just need 32 amps

Hi, I think the 12v rails total 36A. But I'm not sure if i'm reading that correct:

http://www.overclock3d.net/image.php?id=1944

[zulquar]

ya guess i was right 36 a on the 12 v rails is not nearly enough for the beast ... it need atleast 45-50 A ..... a single hd 4870 needs 32 A hope this helped

[plowman]

ya guess i was right 36 a on the 12 v rails is not nearly enough for the beast ... it need atleast 45-50 A ..... a single hd 4870 needs 32 A hope this helped

The issue is resolved now. I realised it was jumping up to the correct speeds once in full screen mode. Thank you anyway. I think i'll look into a new PSU as it does appear mine may be lacking somewhat...

[batmeat]

Hmm..
I'm wondering if the GPU doesn't have some kind of power saving mode, when it's not under load.
The only thing I would know to do is check it while it's under load.(playing a game)
I know rivatuner has a option to have a little read out in the corner of FPS, and core/mem clocks too. But I don't remember how to set that up.
But I would say check it in a game, and see what the clock values show then.

My 4850 ran on a saver mode until it was needed. Once I started gaming or physically stressed it is when it would pick up.

[batmeat]

ya guess i was right 36 a on the 12 v rails is not nearly enough for the beast ... it need atleast 45-50 A ..... a single hd 4870 needs 32 A hope this helped

I'm feeling weird now, I don't count 36a on the 12v rails. How are you counting it?

[batmeat]

Power supply says 36, but I only calculate 34.2 by math. Im sure it's close enough.