bottle necking my cpu? or what else may be wrong?

[eskamobob1]

hey guys,

i have recently upgraded to 3x 5870 in my mining rig, how ever, when i run all three, one will run at around 270MHash/s, and the other two will be below 100 MHash/s... when i run just one it runs at right around 300, but even with a 150MHz OC it wont go above 320... i was wondering if i am possibly bottle necking my CPU as it is prity old, or if something else may be going wrong

my system specs are:

CPU: pentium d 840 (3.2GHz)
Mobo: 780i ultra
RAM: 4x1GB bargain brand PC2-4200
CPU cooler: h70
case: HAF X (full fans)
GPU: 3x gigabyte GV-R587UD-1GD
PSU: 1600W ultra X4

any thoughts are welcomed

thank you in advance

[1714176119]

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[bmgjet]

That cpu should be fine for a few Ghash/s since its the gpu that does all the work.

[k9quaint]

The probably is most likely with your drivers. I had a 2 core CPU maxed out at 100% just running 2 GPUs due to a bug in the catalyst drivers. Which OS and driver version are you running?

I have 11.6 Catalyst + Linux working with <10% CPU util.

11.7 Catalyst showed the same symptoms you see.

[eskamobob1]

i have 11.7 and im running windows XP... im planning on going linux as soon as i can make this a dedicated machine... how would i go about downgrading to 11.6... is there a simpler way than fully un installing and re installing the drivers?

[k9quaint]

Uninstall and reinstall is the recommended method.

[eskamobob1]

ok... kwl... im trying that now

[eskamobob1]

i just realized that i am on 11.6... i am about to try 11.7 and hope for the best... plz let me know what drivers you guys had the most success with

[eskamobob1]

11.7 has an even worse effect... on willnow run at around 270 wile the others run below 10 ... what drivers are you guys using?

[drawoc]

Just to be sure, do you have dummy plugs on the extra cards? (Windows needs them, Linux doesn't)

[eskamobob1]

yes i do

[eskamobob1]

one more bump... and i am currently testing out 11.5.. it is running better than previous versions, but still only at 450-500MHash/s for 2 cards

[eskamobob1]

all i have running in the background is task manager... and with it closed or open, there is not difference in MHash/s

[eskamobob1]

bump again... whats the best driver for mining with 5870s?

[eskamobob1]

Bump... I have figured out why my mhash/s is lowering on my second and 3rd card... They down clock them selves when I turn them on... I can only asume this is because of heat... So what do you guys use to keep your temps down? I hit 100c plus with all three cards on, and the middle and top cards hits 95 when I only have two running (bottom and middle or top is the same result)... Any suggestions are welcome, but my comp is in my room so using 190CFM fans in the GPU duct in the HAF X is not an option (I have tried )

[Beta-coiner1]

Bump... I have figured out why my mhash/s is lowering on my second and 3rd card... They down clock them selves when I turn them on... I can only asume this is because of heat... So what do you guys use to keep your temps down? I hit 100c plus with all three cards on, and the middle and top cards hits 95 when I only have two running (bottom and middle or top is the same result)... Any suggestions are welcome, but my comp is in my room so using 190CFM fans in the GPU duct in the HAF X is not an option (I have tried )

Use a good third party thermal compound on your GPUs.It is possibly the cheapest way....but kinda precarious if you don't know where and how to put the goo on.

I have seen temps drop 8-15 C depending on the GPU.

[PLaci1982]

If there are mounting places in your case for fans put as much possible in!

I did put in 1x 80mm, 1x 90mm Noctua coolers, and my 100-105°C cards with max ~75% load dropped to 75-85°C at 100% load!

[SMOKEU]

I got sick of 11.6 because it kept making my computer freeze when I watched videos and mined simultaneously, so I switched to 11.7 and the problem went away, but now my CPU usage is higher.

[PLaci1982]

I got sick of 11.6 because it kept making my computer freeze when I watched videos and mined simultaneously, so I switched to 11.7 and the problem went away, but now my CPU usage is higher.

Sad, but all that are know differences between 11.6 and 11.7...
https://bitcointalk.org/index.php?topic=33613.0

[gtrrkicw]

I have the same issue with my CPU usage being extremely high. I am running a 5770 on an AMD X4 and it uses up a whole core to keep up with the miner. Is this a problem with the Catalyst driver? I really don't know what else it could be.

[Dargo]

Bump... I have figured out why my mhash/s is lowering on my second and 3rd card... They down clock them selves when I turn them on... I can only asume this is because of heat... So what do you guys use to keep your temps down? I hit 100c plus with all three cards on, and the middle and top cards hits 95 when I only have two running (bottom and middle or top is the same result)... Any suggestions are welcome, but my comp is in my room so using 190CFM fans in the GPU duct in the HAF X is not an option (I have tried )

Have you considered going caseless? From what I have read, it's going to be tough keeping 3x5870s cool in a case, especially if they are close together. I have enough trouble with my 2x5850s in a case, and will be going caseless soon. I know, if they are in your room, you don't want a caseless mess, but it may be the best way to keep the cards cool. If you are handy with tools, I think it isn't that hard to build an open air case that is relatively tidy. I've built an aluminum frame that I might cover with some mesh screen, and I think the end result will look OK.