CrossFire Woes - need *Help* 2900xt/2900p

[apoppin]

Updated:

The solution was to Use CCC's OverDrive and i had to *Fool* CCC with 2 alligator clips and some wire - attaching each clip to the "extra" uncovered 2-pins in each 8-pin connector and grounding the wire. CCC then set everything up OK and we settled on a [for now] core speed of 697mhz [up from the Pro's 506 but down from the XT's 743] and memory at the XT's stock speed ... about +30% increase ... 3DMark06 increased from 10500>13090 and some DX10 games became "playable" ... and it looks like a "keeper'

Many thanks for your assistance and suggestions

=========================================


My rig is in Sig ... my P35 MB has a 16x and a 4xPCIe slot

i have a 2900xt 512-bit/512 MB [in the 16x slot] and a 2900pro 256-bit/512MB in the 4x slot and am attempting to CrossFire them. i now have 2 Interconnect Bridges and i have the extra Power to the MB for Xfire connected, 2 PCIe connectors - 1 to the 2900xt and 1 to the 2900pro and a 2nd molex to PCIe cable into the 2nd connector of the 2900xt. i have also switched cables around to make sure one rail is not overloaded. Everything looks fine with voltages.

The *problem* is that when i go into CCC i see a "!" ... and read "Your system is not functioning at optimal performance. Please go to the diagnostics page for a more detailed analysis." When i go to the diagnostic page there is *nothing* noted.

"Enable CrossFire" is checked ... BUT when i look at the "Graphics Adapter:" all i see is "1. ATI Radeon HD2900XT [Synch Master] ... no 2nd GPU
- it does show in "System Information" 2900Pro is on IRQ 429496293 and the 2900xt is on IRQ 429496293 both with "OK" status. And it is the same for Vista 32 or Vista 64. i have uninstalled and reinstalled 2 sets of drivers 7.12/8.1 with the same lack of results.

*Worst of all* ... my 3DMark06 score [representing how little performance increase there is with it "enabled"] only went from 10500 marks to 12500 marks. And to add insult to injury, i can't OC it ... not Riva Tuner nor AT tray tools nor AMD GPU Clock tool. Of course i am also using the latest betas as the certified ones are old. i see no settings for games or 'profiles' to enable.

So i figure i am doing something wrong ... It *should* work. Well, it IS working ... but clearly - at present - it is not much of a worthwhile performance increase.


http://ati.amd.com/technology/crossfire/charts.html

if all i can get is 15% improvement ... 2900pro is going back to NewEgg for refund ... i am quite satisfied with a single 2900xt for DX9 games.

 

[thilanliyan]

Can you Crossfire a 256-bit card with a 512-bit card? Would that make a difference?

Here's some mixed 3870/2900 Xfire results...maybe you can find something in that article:
http://www.driverheaven.net/reviews/3870-XXX/mixed.php

 

[Spikesoldier]

save your bios from the 2900pro and flash the XT with it. worst case you have the pro to flash back the xt.

im thinking that the driver/CCC is not liking the different deviceIDs on the two cards.

this will at least rule out that mixing those two cards is causing the error.

 

[thilanliyan]

Originally posted by: Spikesoldier
save your bios from the 2900pro and flash the XT with it. worst case you have the pro to flash back the xt.

im thinking that the driver/CCC is not liking the different deviceIDs on the two cards.

this will at least rule out that mixing those two cards is causing the error.

Considering one is 512 bit and the other is 256 bit is that a smart idea? He might end up with a paper weight.

 

[Spikesoldier]

Originally posted by: thilan29

Originally posted by: Spikesoldier
save your bios from the 2900pro and flash the XT with it. worst case you have the pro to flash back the xt.

im thinking that the driver/CCC is not liking the different deviceIDs on the two cards.

this will at least rule out that mixing those two cards is causing the error.

Considering one is 512 bit and the other is 256 bit is that a smart idea? He might end up with a paper weight.

even if the card doesnt like the bios, it can still be flashed back with the help of his second VGA card.

and of course, remember to save the XT bios as well.

 

[apoppin]

Originally posted by: thilan29

Originally posted by: Spikesoldier
save your bios from the 2900pro and flash the XT with it. worst case you have the pro to flash back the xt.

im thinking that the driver/CCC is not liking the different deviceIDs on the two cards.

this will at least rule out that mixing those two cards is causing the error.

Considering one is 512 bit and the other is 256 bit is that a smart idea? He might end up with a paper weight.

thanks for the quick suggestions

you can usually flash them back ... but if not it IS a big problem ... i'd prefer not to flash it's BIOS.

i don't believe that 256-bit vs. 512 bit was supposed to make much of a difference and they were evidently running 1950 series this way.

Why does CCC show only one 2900xt?

 

[Spikesoldier]

Originally posted by: apoppin

Originally posted by: thilan29

Originally posted by: Spikesoldier
save your bios from the 2900pro and flash the XT with it. worst case you have the pro to flash back the xt.

im thinking that the driver/CCC is not liking the different deviceIDs on the two cards.

this will at least rule out that mixing those two cards is causing the error.

Considering one is 512 bit and the other is 256 bit is that a smart idea? He might end up with a paper weight.

you can usually flash them back ... but if not it IS a big problem ... i'd prefer not to flash it's BIOS.

i don't believe that 256-bit vs. 512 bit was supposed to make much of a difference and they were evidently running 1950 series this way.

Why does CCC show only one 2900xt?

not sure why one is showing but i am reminded of the 9500np being able to transform into a 9700np.

this was only possible by getting a card with the L-shaped memory pattern, on the 9700's PCB. at the time to meet demand, 9500np's were being built on these "surplus" PCB's. if the original card was being marketed as a 128 and the bios being a 9500np, i think that running at a lower bus width should work.

something tells me that you wont have problems as long as the new BIOS isnt trying to address/work on a wider bus width that is there physically.

 

[Sylvanas]

'Graphics adapter' in the CCC, to my knowledge- should show the card that the DVI cable is plugged into ie. the one that drives the monitor. If Crossfire is checked to 'enabled' and you can see two adaptors in the Overdrive tab then that indicates Crossfire is active. You have demonstrated there is an improvement in 3dmark so that must imply Crossfire is working, for the best scores Id suggest lowering all settings in the CCC and then re-running 3Dmark (AA/AF/Mipmap bias) additionally try the Catalyst AI set from 'Standard' to "advanced' and see if theres a difference. 'Standard uses Crossfires 'Supertiling' 'scissor mode' and I think theres another....setting 'Advanced' Forces AFR (alternate Frame rendering) which can net very substantial performance gains. I am not really that surprised as 2000 marks is what I'd expect from that setup- remember 3dmark is highly CPU dependant so I'd say to you that Crossfire is functioning fine its just that maybe a 256bit/512bit setup doesn't quite bring what you would have hoped.

You said you had 2 pci-e connectors and 1 6pin molex? So thats two 6pin connectors to the 2900XT and only 1 to the Pro? it was my understanding that the Pro also required a minimum of 2 6 pin connectors thus you would be short by 1?

EDIT: Yes I'd be 99% sure a bios Flash using a 512bit bios would brick the Pro. What performance are you getting in games?

 

[apoppin]

Originally posted by: Sylvanas
'Graphics adapter' in the CCC, to my knowledge- should show the card that the DVI cable is plugged into ie. the one that drives the monitor. If Crossfire is checked to 'enabled' and you can see two adaptors in the Overdrive tab then that indicates Crossfire is active. You have demonstrated there is an improvement in 3dmark, for the best scores Id suggest lowering all settings in the CCC and then re-running 3Dmark (AA/AF/Mipmap bias) additionally try the Catalyst AI set from 'Standard' to "advanced' and see if theres a difference. 'Standard uses Crossfires 'Supertiling' 'scissor mode' and I think theres another....setting 'Advanced' Forces AFR (alternate Frame rendering) which can net very substantial performance gains. I am not really that surprised as 2000 marks is what I'd expect from that setup- remember 3dmark is highly CPU dependant so I'd say to you that Crossfire is functioning fine its just that maybe a 256bit/512bit setup doesn't quite bring what you would have hoped.

You said you had 2 pci-e connectors and 1 6pin molex? So thats two 6pin connectors to the 2900XT and only 1 to the Pro? it was my understanding that the Pro also required a minimum of 2 6 pin connectors thus you would be short by 1?

EDIT: Yes I'd be 99% sure a bios Flash using a 512bit bios would brick the Pro. What performance are you getting in games?

Minimal performance increase in some games ... a couple of FPS at best.

There is *NO OverDrive* tab.

and looking in Device Manager everything looks normal with the Pro and the XT showing up properly.

from that DriverHaven article:

Initially we installed the 3870 as the card in the primary PCIe connector and the 2900 XT in the second 16x PCIe slot (CrossFire bridge also installed). In this configuration both cards were seen by Windows and the ATI installer reported successful install of the Catalyst drivers. After rebooting we checked device manager and although the cards were both listed the 3870 had a warning message beside it and was not fully working.

Before we gave up on this idea we decided to have one last attempt and switched round the cards so that the 2900 XT was the primary and the 3870 was the secondary. Once again both cards were recognised by Windows and once again the ATI installer reported success on driver install. We rebooted and to our surprise device manager reported both cards as working.

You don't think i should switch PCIe slots should i?
:Q
-that would set the 256bit card as the primary card
-but then my device manager is NOT reporting any problems as theirs was.


and my 2900pro has only *one* PCIe connector - normal for the 256bit Pro, i think.

i will try your other CCC suggestions


and my Catalyst AI is always set to 'advanced' ... i think 2900xt likes it
but where is setting 'Advanced' AFR?

 

[lavaheadache]

I'm willing to bet the CCC is saying "not optimal" because the cards are mismatched. I'm also willing to bet that 3dmark is totally limited by your moderately clocked Dual core. 3.1 is moderate considering people have 3.8 + quads out there. Have no worries, I'm sure if you owned 3dmark and could change the resolution, you would see much higher gains. My average clocked e6600 (3.5) limits my sli'ed gt's. With a single GT I score 12k... going to sli cards I get 15.5k. now in a perfect world I'd wish to see 24k. In games I get pretty good scaling so I'm not too worried about 3dmuck scores.

 

[Sylvanas]

Originally posted by: lavaheadache
I'm willing to bet the CCC is saying "not optimal" because the cards are mismatched. I'm also willing to bet that 3dmark is totally limited by your moderately clocked Dual core. 3.1 is moderate considering people have 3.8 + quads out there. Have no worries, I'm sure if you owned 3dmark and could change the resolution, you would see much higher gains. My average clocked e6600 (3.5) limits my sli'ed gt's. With a single GT I score 12k... going to sli cards I get 15.5k. now in a perfect world I'd wish to see 24k. In games I get pretty good scaling so I'm not too worried about 3dmuck scores.

Indeed, and you are probably going to be seeing better increases with a 3.1 dual E4300 in a more GPU limited resolution if thats possible, so I'd be setting things as high as possible in games just to test that.

but where is setting 'Advanced' AFR?

'Advanced' Forces AFR as of Cat 6.7 as noted here

The Crossfire modes are also mentioned here

more info if you Google 'Crossfire AFR' aswell

 

[apoppin]

Originally posted by: lavaheadache
I'm willing to bet the CCC is saying "not optimal" because the cards are mismatched. I'm also willing to bet that 3dmark is totally limited by your moderately clocked Dual core. 3.1 is moderate considering people have 3.8 + quads out there. Have no worries, I'm sure if you owned 3dmark and could change the resolution, you would see much higher gains. My average clocked e6600 (3.5) limits my sli'ed gt's. With a single GT I score 12k... going to sli cards I get 15.5k. now in a perfect world I'd wish to see 24k. In games I get pretty good scaling so I'm not too worried about 3dmuck scores.

you may well be right . ... well then, i already have about 9 more benchmarks set up ... i will run them and see what happens ... and report back

it just didn't look right - especially with the warning and only one GPU showing up in CCC ... also the inability to set or hold an OC ... and i will also push my OC over 3.15Ghz

Note: As of the 6.7 Catalysts, Crossfire users should set Catalyst A.I. to Advanced to force Alternate Frame Rendering (AFR) mode in all Direct3D games for optimal performance. Once again, Catalyst A.I. should only be disabled for troubleshooting purposes, such as if you notice image corruption in particular games.

i always set it to advanced ... i wasn't sure if there was another tab i was missing

The CrossFire rendering mode is selected automatically if the Catalyst A.I. feature is enabled. In this case the choice depends on the API employed by the particular application: SuperTiling for Direct3D and Scissor for OpenGL. AFR is used only when there?s an appropriate application profile in Catalyst. If Catalyst A.I. is disabled, SuperTiling is used for Direct3D games and Scissor in all other cases. The Super AA mode is automatically activated as soon as 8x/10x/12x/14x FSAA is turned on.

yeah, i thought it was automatic ... again i was concerned i needed to "set" something special. Adaptive AA is enabled and it is set for 'quality' and Super-sampling

 

[happy medium]

You don't think it's because your running your 2900pro in 4x pci-e mode?
I believe your 2900xt is being slowed to the 2900pro's (in a 4x slot) pace.
Normal crossfire nets what 40/70% increase? A 4x pci-e slot will lose you 15/20% peformance on higher end cards.

 

[apoppin]

Originally posted by: happy medium
You don't think it's because your running your 2900pro in 4x pci-e mode?
I believe your 2900xt is being slowed to the 2900pro's (in a 4x slot) pace.
Normal crossfire nets what 40/70% increase? A 4x pci-e slot will lose you 15/20% peformance on higher end cards.

i *see* the problem .... according to RT my 2900xt should run at 743 Mhz/1656 ...
BUT ... it is slowed down to Pro speeds ... an ungodly low 506/1026

RT will not "apply" OC'd setting to the Pro and will reset to default when i click OK.

IF i could OC the pro to xt speeds - or even fairly close - THEN i would get a solid performance increase as it is ... i bare gain anything

i.e.

F.E.A.R. built-in Demo

16x10 everything maxed 0xAA/16xAF - SS on

XT/stockPro - Vista 64 - 30 Min/59 Avg/112 Max
xt/OC'dpro- Vista 64 - 32 Min/70 Avg/113 Max

===================

Call of Juarez DX10 benchmark

-16x10- High Shadows/Shader Map - 2048x2048

xt/stock Pro -Vista 64 - 15.9 Min/20.7 Avg/49.3 Max
xt/OC'd pro- Vista 64 - 14.3 Min/22.6 Avg/45.8 Max

============

IF you are right then i should *reverse* cards and put the 2900xt in the 4x slot ...
-it will be bandwidth limited but i might be able to OC the pro.
make any sense?


btw, under load my Pro is running in the 90s and my Pro barely breaks into 70C.
-i am amazed that my airflow and case temps are decent and it is barely any louder [because the pro is quiet]

i *would* consider getting another 2900xt instead - i actually got a good offer for a trade of my 2900p + cash - but i am concerned that 850w might not be enough for both power hungry cards ... i shuldda got the 1000w
:roll:

 

[lavaheadache]

Originally posted by: apoppin

i *would* consider getting another 2900xt instead - i actually got a good offer for a trade of my 2900p + cash - but i am concerned that 850w might not be enough for both power hungry cards ... i shuldda got the 1000w
:roll:

Your power supply is plenty

 

[apoppin]

Originally posted by: lavaheadache

Originally posted by: apoppin

i *would* consider getting another 2900xt instead - i actually got a good offer for a trade of my 2900p + cash - but i am concerned that 850w might not be enough for both power hungry cards ... i shuldda got the 1000w
:roll:

Your power supply is plenty

it lacks connectors and will be maxed out

BUT ... wth can't i OC - at all?
-Riva Tuner *refuses* to apply settings


i know the pro should be able to match the XT speeds in the RAM and it should get close in the core ... shall i reverse the cards in the slots?

 

[Sylvanas]

Might aswell try it, reverse them and see what happens. If not, you could flash new speeds for the Pro via the BIOS. Use Foxconns 2900 Bios flash utility you will have to sign up to download it however its a great tool, I've used it many times (can also set voltages etc). Have you tried operating Rivatuner when Crossfire is disabled? I Don't use Rivatuner to OC my 3850's as I have Overdrive but I vaguely remember that people with SLI/Crossfire setups say that Rivatuner isn't exactly the most friendly application for OCing a multiGPU configuration, and that you need to disable Crossfire or something then set the OC'd settings then re-enable it for it to work (correct me if I'm wrong).

 

[MegaWorks]

No offence apoppin but I would take the Gigabyte P35-DS3P and throw it in the garbage.

Do yourself a favor and get an X38 board, this 4x thing is giving me head pain. I'll start taking drugs after this.

Edit: About your PSU, I think you only have 2 PCI-E connectors you might consider a new PSU for a stable configuration. BTW 850W is plenty of power well unless you're doing CPU overclocking.

 

[heyheybooboo]

Originally posted by: MegaWorks
No offence apoppin but I would take the Gigabyte P35-DS3P and throw it in the garbage.

Do yourself a favor and get an X38 board, this 4x thing is giving me head pain. I'll start taking drugs after this.

Edit: About your PSU, I think you only have 2 PCI-E connectors you might consider a new PSU for a stable configuration. BTW 850W is plenty of power well unless you're doing CPU overclocking.

I think the wattage on the PS is enough. I've seen people say you can OC the 2900pro with 2x3-6pin and others say you need 2x4-8pin. I'm trying to find a PS with a bunch of 2x4-8-pin connectors.

It doesn't help when you get 2x3's with the video card :disgust:

A PCIe1.1 x16 slot with 4 lanes has about the same bandwidth as 4x AGP....

 

[apoppin]

Originally posted by: Sylvanas
Might aswell try it, reverse them and see what happens. If not, you could flash new speeds for the Pro via the BIOS. Use Foxconns 2900 Bios flash utility you will have to sign up to download it however its a great tool, I've used it many times (can also set voltages etc). Have you tried operating Rivatuner when Crossfire is disabled? I Don't use Rivatuner to OC my 3850's as I have Overdrive but I vaguely remember that people with SLI/Crossfire setups say that Rivatuner isn't exactly the most friendly application for OCing a multiGPU configuration, and that you need to disable Crossfire or something then set the OC'd settings then re-enable it for it to work (correct me if I'm wrong).

*reversing* the cards doesn't work at all ... there is instability and frames appear to to be getting "ahead" of each other

i am not so sure i want to mess with the Pros BIOS ... it *should* work ... but if it doesn't it is a $150 loss ... i need to think about that


the PROBLEM is that i simply cannot OC the Pro ... the OC cannot be "saved" it will not "apply"

========

Originally posted by: MegaWorks
No offence apoppin but I would take the Gigabyte P35-DS3P and throw it in the garbage.

Do yourself a favor and get an X38 board, this 4x thing is giving me head pain. I'll start taking drugs after this.

Edit: About your PSU, I think you only have 2 PCI-E connectors you might consider a new PSU for a stable configuration. BTW 850W is plenty of power well unless you're doing CPU overclocking.

It sounds like you were already taking drugs before you posted your 'help' ... let me find some things in your rig i would toss. - this is the kind of advice i do not need or want - sure buying a GTX ultra would *also* 'solve' my problem or a 3870x2.
--The PS is sufficient. The MB is not a problem [period] ... 4x PCIe is no bandwidth killer
--Both 2 Cards only need *three* PCIe connectors - two for the XT and one for the Pro ... two come right from each rail and i use another one as a molex to PCIe connector for the 2nd connector on the XT.

IF i had another 2900xt, then i would need another molex to PCIe connector and at that point it might be marginal indeed ... it is not the PS and it is not the MB and i am neither upgrading my MB nor my PS ... if i cannot get the Pro OC'd then it simply goes back to NewEgg for a RMA REFUND ... minimal 'loss' and much education


Help me find a way for me to OC my PRO ... preferably without flashing the BIOS ... disabling Crossfire and trying to "save" still doesn't work
---and i have tried RivaTuner/AMD GPU clock tool and ATT tool ... the OC simply doesn't "save"

i bet is is something 'simple'
--i might get so *desperate* i may even ask AMD for help
:Q

 

[MarcVenice]

4x is not a bandwith killer ? You sure about that ? I've seen reviews where high-end cards ended up 10% slower on 8x pci-e then on 16x pci-e. 16x is to much, but I think 4x isn't enough.

 

[nitromullet]

Help me find a way for me to OC my PRO ...

It sounds to me that your best bet would be to the bench the hell out of the Pro by itself to find its max STABLE clocks, and then flash the BIOS with those clocks to OC the card. This way you won't have to worry about OC'ing it with RT or CCC. Don't get me wrong, I'm not certain I would want to go through all that myself just to try something out, but it seems like that would work.

edit: I saw that you just edited your post with regards to flashing...

I don't blame you. It would make more sense just to return the the Pro, sell the XT, and replace them both with an HD3870X2 than it would to buy a new motherboard and PSU just to run either the XT/Pro combo at 16x/16x or dual XT's....

 

[SlowSpyder]

I have no real world experience with Crossfire or SLI, but based on what I know I really do think you will have an issue running a 512bit card with a 256bit card. The software can throttle down the XT core, or you could overclock the Pro core to the same speed, that fixes that issue. I doubt that CF is smart enough to automatically cut the 512bit bus in half. You are running two cards that have different memory bandwidths... unless CF is smarter then I realize and it can do that.

 

[apoppin]

Originally posted by: nitromullet

Help me find a way for me to OC my PRO ...

It sounds to me that your best bet would be to the bench the hell out of the Pro by itself to find its max STABLE clocks, and then flash the BIOS with those clocks to OC the card. This way you won't have to worry about OC'ing it with RT or CCC. Don't get me wrong, I'm not certain I would want to go through all that myself just to try something out, but it seems like that would work.

edit: I saw that you just edited your post with regards to flashing...

I don't blame you. It would make more sense just to return the the Pro, sell the XT, and replace them both with an HD3870X2 than it would to buy a new motherboard and PSU just to run either the XT/Pro combo at 16x/16x or dual XT's....

now that IS a good idea ... but i am not going to buy anything else
:thumbsup:
--IF i can't get this to work, i will just *wait* for nextgen GPU ... a 3780x2 doesn't turn me on. Actually flashing the BIOS of a Videocard is about 95+% certain ... you can certainly flash it back - i have even REflashed blind and i have never lost a GPU ...

==============

Originally posted by: SlowSpyder
I have no real world experience with Crossfire or SLI, but based on what I know I really do think you will have an issue running a 512bit card with a 256bit card. The software can throttle down the XT core, or you could overclock the Pro core to the same speed, that fixes that issue. I doubt that CF is smart enough to automatically cut the 512bit bus in half. You are running two cards that have different memory bandwidths... unless CF is smarter then I realize and it can do that.

Well, they got a 2900xt and a 3870 to run OK in Xfire and they even OC'd it ...
CCC is pretty smart

i believe i need to set this issue straight - 256bit vs 512bit in Xfire ... so that means i better ask AMD ... research tonight
- when will i EVAR play any G-D games before i get old and senile?

 

[SlowSpyder]

In the link where the 2900XT and the 3870 are running in Crossfire, only the first graph shows a 3870CF vs. the 3870/2900CF. You can see that the performance of a 2900 and 3870 running in CF is much less then two 3870's running in CF. Technically it 'works' but it doesn't look like it works well.... just like what you are experiencing.