Hi bro i just did a round of the things u mentioned and so far no go. it seems like poclbm and diablo miner just freezes at 50% cpu load when ever dual cards of 5970 or 6990 are added to the system without xfire.

I guess i will just xfire and run inefficiently till amd fixes this issue

But thanks for ur guide!

Bro thanks for sharing I will try that on the dual 6990 now~!!

So you were saying that during the installation of drivers dont plug in the dummy plugs ?

Hi I am curious could you lay out the order in which u carry out this trick?

Hi diablo, thanks for the prompt reply. I have a plan now and that is to mix my dual 6990 with the 5850 + 5970. Hopefully windows will recognise both as opencl and no need to run xfire. =P

Wait I dont quite get the part OS kernel scheduler timeslice length. What I do face is a huge drop in hash/s when i go lower than -f 15, at -f 2 its almost 600mhash/s so thats why i up the -f number to go it to run at 1ghash

Hey is there an option for internal xfire for a 6990? I looked and didnt have the same option as that in the 5970 CCC. Could I have missed out some thing? THanks for your help anyways =)

Hi Thekid are you running dual 6990? Also what are your CCC settings? I tried launching the older versions of poclbm but they will not run. It seems like no opencl device to them when the dual 6990 are not in xfire. Any particular settings you could share ?

Thanks diablo I guess I will have to make do with the hash rate till amd comes out with the new sdk for 6990. Thanks for your great miner, I am using it for the dual 6990. It hovers around 1ghash/s and its at -f 7777777. Hahah I tested and the numbers seem to slow down the hash rate when its lesser than -f 17 but anything more it hits 1ghash/s constant. Which is nice =)
GPU Max at 93% with powerplay maxed out

I guess ppl shld stay clear of the 6990 series for mining. I am left with no choice but to mine inefficiently. Just invested usd 1.5k on the two cards and they are worst off then the 5970.

Hi diablo I have the dummy plugs in both graphics card. And if I were to disable xfire the cards will not be recognised by the diablo software. Same goes with poclbm.

Yeap both with dummy plugs attached. both diablo2d and poclbm will refuse to start without crossfire enabled.

I am stuck btw a fluctuating hash rate ~1.3ghash to 700mhash (poclbm) and a 1ghash hash rate diablo3d

Hi diablod3 I am facing some issues using this miner with dual 6990. With -f 1 the hash rates drop to a whooping 600000 low. I tested out different flags and found that -f 17 to 20 is the best with the highest at 1ghash/s. This is very stable compared to poclbm which fluctuates from 800mhash to 1.2ghash. I am using 11.3 + 2.4 sdk like u recommend. The preview 11.4 drivers + 2.4 sdk yield the same results. I am using windows 7 64 bit. And the only way to get the software to recognise the dual 6990 is to crossfire them. Any advice u could give me?

Thank you =)

Hi Tycho I think i know what u mean, you are refering to the internal crossfire of 5970 right? I think 6990 might not have that option from the menu. Anyway I am running it in crossfire mode with the non gui version of poclbm. The hash rates however fluctuates alot and can't stay constant. Any solution for that? My previous 5970 + 5850 on that rig can run at 99% load. It really baffles me..But thanks alot for your advice

Hi tycho thanks for the prompt reply, so you are saying that I have to attached the xfire cable?

Also by slaving u mean I can add addition GPUs inaddition to the 2x 6990?

Also which version would u recommend?

thelasttrueone

did u manage to get 2 x 6990 or 2 x 5970 running without xfire in windows 7 with that flag? I tried but it will not run. I am totally at a loss now.

Hi thanks for the replies. I have connected a null adapter and is working as tested when i was using 5850 + 5970. It seems to have the same issue with a pair of 5970. As of now the best that I can get the miner to run is on 3 gpus leaving the 4th gpu to run at 48k. I have also tested each 6990 independently and all works well.

So is it a question of windows + miner not being able to run 2 x 6990 or 2 x 5970? I have tested with crossfire cable attached it works but at a very low hash rate. Without the cable attached and I can get 3 out of 4 gpu cores mining properly. This is a troubling issue as I have just purchased these 6990.

Quick question does windows 7 support 2 x 6990 + 2 x 5970 ? I read some where that it does and some where that it doesnt. Has anyone tested it?

Hi I just bought 2 6990 cards and installed on windows 7 with catalyst 11.4 preview. Running the gui poclbm latest version, the speed shown in the summary page remains connected. I have tried 11.3 and still the same. It works when 1 card is installed and doesn't for all gpu cores when 2 cards are installed. Anyone having the same issue?

Cheers!

Hi trentzb, thanks for the guide. I will see what I can do. Thanks man!

Hi trentzb, the link below is the read out.
http://pastebin.com/jeVuekYf