MORE Crossfire issues, more of the same... - Page 3 - Overclock.net

Vlasov_581 · 08-10-08

k....how about you pull one card out and 3D mark, take a screenshot, the put it back in and run it again....

blitz6804 · 08-10-08

Okay, first off:

CPU score has a bigger impact on SM2/3 than I recall. However, the scores do not reflect well on the 4850s in this case.

The CPU at 2699 MHz and the RAM at DDR 386 gives:

The CPU at 2802 MHz and the RAM at DDR 400 gives:

A 4% CPU speed increase results in a difference of 0.6 % for SM2, 2.4% for SM3, and 3.9% CPU. Overall difference in the score is 2.2%.

In any event, we see there must be a problem. With a slower CPU and slower RAM, my 3850 gets 91 more 3DMarks overall and 32 more SM2 marks. Yes, I get 270 fewer SM3 marks. However, one 3850 should not be about the same as a pair of 4850s.

(For the record, our friend can gets about 11,129 overall with his single-video-card K8. I have seen dual cards much higher.)

Xyro TR1 · 08-11-08

I get essentially the same score w/ one card as I do two. Any more ideas?

**grunion** · 08-11-08

Quote:

Originally Posted by Xyro TR1

I get essentially the same score w/ one card as I do two. Any more ideas?

What's your CPU speed during the test, also the cpu score?

Can you run any Source benchmarks?

Xyro TR1 · 08-11-08

^Do not have source.

CPU is at a stock 2.4Ghz
CPU Score is ~182#

**grunion** · 08-11-08

Quote:

Originally Posted by Xyro TR1

^Do not have source.

CPU is at a stock 2.4Ghz
CPU Score is ~182#

D/L clocktool
Make sure both cards are recognized, also make sure both PCI-E lanes are at maximum bandwidth.

Xyro TR1 · 08-11-08

Quote:

Originally Posted by grunion

D/L clocktool
Make sure both cards are recognized, also make sure both PCI-E lanes are at maximum bandwidth.

Both cards show up, both running at x16.

Link Speed: 2.5 GT/s

**grunion** · 08-11-08

Quote:

Originally Posted by Xyro TR1

Both cards show up, both running at x16.

Link Speed: 2.5 GT/s

I'm at a loss, I honestly think it's your proc dragging you down.
You need to run a benchmark that isn't so cpu heavy.
Do you have anything you can run besides 3D Marks?

For comparison look at my CF scores, default cpu speed VS. 3.6ghz with no gpu oc.

My default sm scores are not much more than yours, but look at the score skyrocket with a cpu oc.

pioneerisloud · 08-11-08

Quote:

Originally Posted by grunion

I'm at a loss, I honestly think it's your proc dragging you down.
You need to run a benchmark that isn't so cpu heavy.
Do you have anything you can run besides 3D Marks?

For comparison look at my CF scores, default cpu speed VS. 3.6ghz with no gpu oc.

My default sm scores are not much more than yours, but look at the score skyrocket with a cpu oc.

Yes and no. For example, my rig all stock scores 8500 (give or take). That's 1.8GHz, card at stock. When I overclock to 3.0GHz, I score over 11k.

However he's running 2.7GHz. So its kind of in the middle.

Compare apples to apples here, last night I ran a SINGLE 4850 in my rig at 2.8GHz, and I scored 10006 in 06. So there is most definitely an issue going on here.

Two things I can think of:

Either you have the cards overclocked...and the overclock is too high (its unstable). Or your CPU isn't 100% stable...and that DOES cause your 3DMarks to be lower than they should be. You SHOULD be 9500+ marks with your clocks and a SINGLE 4850.
Power supply may not be able to handle the load. I noticed you've got quite the rig there, 3 HDD's, 2X 4850's, overclocked CPU...you're drawing more power than you think. And my best guess is not enough power.

When I attempted to run SLI'd 8600GTS's (I know I know, but I got them CHEAP), my power supply couldn't handle it. I know this because they did the EXACT same thing you're experiencing now. 3DMark scores went down in SLI over single card. And my games glitched like crazy (may or may not happen to you).

My advice, see if you can get your hands on a more powerful PSU. It wouldn't hurt just to test and see if that's the problem. I honestly can't think of anything else that's the problem. There's absolutely NO reason why you should be under 10k 3DMarks with that system. I break 11k with mine and that's just a SINGLE card.

**grunion** · 08-11-08

He's running his proc at 2.4.
PSU as you mentioned might be an issue, doubtful as it's a good unit.
I run a 3870X2 on a 520HX with 0 issues.

Look at his CPU score, 1,800, that is a score killer if I've ever seen one.
I bumped his cpu score up to 2500 and added 500 to each SMP score and that put him over 11k.

		Overclock.net - Overclocking.net > Graphics Cards > ATI
MORE Crossfire issues, more of the same...

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)