My initial Radeon HD 7970 mining benchmarks

[DiabloD3]

2 x Sapphire Radeon 7970
Corsair 750W PSU

I'm guessing that a slightly higher rated power supply with better efficiency might be called for on this one.

No shit. Corsairs are rated at continuous wattage, and 7970s use 250w each at stock, and you shouldn't exceed 90% of that 750, and you're doing 750-790 at the wall? Holy crap dude.

Go buy one of these: http://ur1.ca/7sqrz

[1714102298]

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[1714102298]

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[1714102298]

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[1714102298]

1714102298

[terrytibbs]

Go buy one of these: http://ur1.ca/7sqrz

Weird short-URL. Redirects to:

Code:

http://www.anrdoezrs.net/click-2150801-104408
97?url=http%3A%2F%2Fwww.newegg.com%2FProduct%2FPro
duct.aspx%3FItem%3DN82E16817116013%26nm_mc%3DAFC-C
8Junction%26cm_mmc%3DAFC-C8Junction-_-Power%2BSupp
lies-_-NZXT-_-17116013&cjsku=N82E16817116013

[DiabloD3]

Go buy one of these: http://ur1.ca/7sqrz

Weird short-URL. Redirects to:

Code:

http://www.anrdoezrs.net/click-2150801-104408
97?url=http%3A%2F%2Fwww.newegg.com%2FProduct%2FPro
duct.aspx%3FItem%3DN82E16817116013%26nm_mc%3DAFC-C
8Junction%26cm_mmc%3DAFC-C8Junction-_-Power%2BSupp
lies-_-NZXT-_-17116013&cjsku=N82E16817116013

Yes, I used a tinyurl because the newegg url is so long.

[enygma]

2 x Sapphire Radeon 7970
Corsair 750W PSU

I'm guessing that a slightly higher rated power supply with better efficiency might be called for on this one.

No shit. Corsairs are rated at continuous wattage, and 7970s use 250w each at stock, and you shouldn't exceed 90% of that 750, and you're doing 750-790 at the wall? Holy crap dude.

Go buy one of these: http://ur1.ca/7sqrz

Keep in mind that the draw from the wall will be about 20% or more greater than the DC load on the PSU. That 750W number is what it is capable of delivering in DC. At 750W at the wall, the PSU may only be delivering around 600W to the hardware (more if the efficiency is better).

[DiabloD3]

2 x Sapphire Radeon 7970
Corsair 750W PSU

I'm guessing that a slightly higher rated power supply with better efficiency might be called for on this one.

No shit. Corsairs are rated at continuous wattage, and 7970s use 250w each at stock, and you shouldn't exceed 90% of that 750, and you're doing 750-790 at the wall? Holy crap dude.

Go buy one of these: http://ur1.ca/7sqrz

Keep in mind that the draw from the wall will be about 20% or more greater than the DC load on the PSU. That 750W number is what it is capable of delivering in DC. At 750W at the wall, the PSU may only be delivering around 600W to the hardware (more if the efficiency is better).

Around 675, iirc their peak efficiency is above 90%. So ~610 watt at the meter is what I'd consider safe.

[1onevvolf]

Idle: ~130W (0 MHash/s)
2 x 925 MHz: ~670W to ~680W (1104 MHash/s) - Power use increases as temps increase
2 x 1125 MHz: ~750W to ~790W (1345 MHash/s) - Power use increases as temps increase
Idle (with OC): ~130W (0 MHash/s)

I'm guessing that a slightly higher rated power supply with better efficiency might be called for on this one.

You could probably shave another 40-60W per card by undervolting. I got 50W off of mine @ 1125MHz which lowered the temps enough (8-9ºC IIRC) to afford running the fans at slower speeds, and others on the forums have been able to undervolt even more than that.

[Parja]

Around 675, iirc their peak efficiency is above 90%. So ~610 watt at the meter is what I'd consider safe.

D3, I think you might have your numbers backwards.  Power at the wall is always higher than the power supplied.  Power supplied is what the PSU is rated for.

Plus, peak efficiency is typically around 50-60% load.  And I don't think there's any 750W Corsair PSU with that kind of efficiency.

Since he didn't actually say what model it is, I'm going to assume a TX750 V2.

Quality review here:
http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story&reid=230

So at the power draw he's at, he's MAYBE getting 85% efficiency.  So 790W draw at the wall is about 670W supplied by the power supply, or a little less than 90% of the power supply's maximum capability.  It's not the most optimal situation, but he's well within the capability of the PSU.  If it was a lesser brand, I'd be concerned, but I wouldn't be too worried about the Corsair unit.

[DiabloD3]

Around 675, iirc their peak efficiency is above 90%. So ~610 watt at the meter is what I'd consider safe.

D3, I think you might have your numbers backwards.

Yes, but what comes out of the wall is what is being used total. So. Something.

Did I mention I hate math?

[Shibby]

I found that the lower the GPU clock is, the lower you can take down your memory clock. Works the same the other direction. Currently I have mine at 1100MHz GPU and 950MHz. That's the lowest I could get my memory clock with the GPU clock like it is, without it jumping up to stock speed. Fan is at 61% and temp is a solid 66C. Average 650 MHash/s. I wish I could figure out a way to lower the memory clock more to keep temps even lower so I can turn the fan down. I can't undervolt either because even in afterburner, after I enable volt changing, it won't let me change the voltage. Any ideas on that one?

[DTHCND]

Hmm. Might try a 7970 out! (Me and some guys are building a rig).

Out of curiosity, does anyone know if I can use a garbage CPU/mobo/RAM? (Ya, I'm a noob at mining).

[kano]

Hmm. Might try a 7970 out! (Me and some guys are building a rig).

Out of curiosity, does anyone know if I can use a garbage CPU/mobo/RAM? (Ya, I'm a noob at mining).

Yes, CPU plays only a very small part in mining on linux ...
CPU's will typically downclock while mining and still used < 5%

[DeathAndTaxes]

Hmm. Might try a 7970 out! (Me and some guys are building a rig).

Out of curiosity, does anyone know if I can use a garbage CPU/mobo/RAM? (Ya, I'm a noob at mining).

Yes my rigs use Sempron single core (watch out the OEM version has no fan), 2GB cheapo ram (1GB might work but 2GB is so cheap), no HDD, and 4GB USB drive running Linux.  It was Linuxcoin but now is the Linux install kano has in his signature above.

[DTHCND]

Hmm. Might try a 7970 out! (Me and some guys are building a rig).

Out of curiosity, does anyone know if I can use a garbage CPU/mobo/RAM? (Ya, I'm a noob at mining).

Yes my rigs use Sempron single core (watch out the OEM version has no fan), 2GB cheapo ram (1GB might work but 2GB is so cheap), no HDD, and 4GB USB drive running Linux.  It was Linuxcoin but now is the Linux install kano has in his signature above.

Thanks! I was actually thinking of using a Sempron! Thanks for the help!

[Anvi]

1225MHz @1225mV / 366 MHz (1500mV)
seems to be high as I can go without display artifacts.
This yields avg ~725MH/s and temperature is 80 degrees on fan 55% setting.

Phoenix settings:
-k poclbm WORKSIZE=64 VECTORS1 DEVICE=0 AGGRESSION=11

[jCole]

1225MHz @1225mV / 366 MHz (1500mV)
seems to be high as I can go without display artifacts.
This yields avg ~725MH/s and temperature is 80 degrees on fan 55% setting.

Phoenix settings:
-k poclbm WORKSIZE=64 VECTORS1 DEVICE=0 AGGRESSION=11

nice man! good luck

[Shibby]

Anyone know how to get the memory clock on the 7970 lower? If I lower it more than 950 mhz, it jumps up to stock speeds. I can't control the voltage in afterburner, and Trixx won't let me lower it, only raise it.

[Fiyasko]

Anyone know how to get the memory clock on the 7970 lower? If I lower it more than 950 mhz, it jumps up to stock speeds. I can't control the voltage in afterburner, and Trixx won't let me lower it, only raise it.

Have you enabled UnOffical Overclocking in MSIa?

[Shibby]

Anyone know how to get the memory clock on the 7970 lower? If I lower it more than 950 mhz, it jumps up to stock speeds. I can't control the voltage in afterburner, and Trixx won't let me lower it, only raise it.

Have you enabled UnOffical Overclocking in MSIa?

I enabled voltage control but it still won't let me change it even after restarting the program. I didn't see the option you're talking about though.

[Fiyasko]

Anyone know how to get the memory clock on the 7970 lower? If I lower it more than 950 mhz, it jumps up to stock speeds. I can't control the voltage in afterburner, and Trixx won't let me lower it, only raise it.

Have you enabled UnOffical Overclocking in MSIa?

I enabled voltage control but it still won't let me change it even after restarting the program. I didn't see the option you're talking about though.

http://forums.guru3d.com/showthread.php?t=338906
Here, You need to edit the config file

[Shibby]

Anyone know how to get the memory clock on the 7970 lower? If I lower it more than 950 mhz, it jumps up to stock speeds. I can't control the voltage in afterburner, and Trixx won't let me lower it, only raise it.

Have you enabled UnOffical Overclocking in MSIa?

I enabled voltage control but it still won't let me change it even after restarting the program. I didn't see the option you're talking about though.

http://forums.guru3d.com/showthread.php?t=338906
Here, You need to edit the config file

Thank you