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Hey guys,

 Quick question. Out of all the vendors out there... Who makes the best 6970 that produces the most megahash. I have been using xfx 6950's for awhile but, wanted to see what your thoughts were before i upgraded to 6970's. Thanks.

I don't have any 6970s, but I have a bunch of other cards XFX asus and gigabyte 5850s and 6950, XFX seem to be made the cheapest and lock the features the most. My XFX 6950s are complete crap practically no heat sink on them

I can't speak for others, but I stick with sapphire due to the performance and statistics of the first one I bought. They all are comparable to the first one in terms of P and S.

Here are my numbers (880(stock) Mhz core, 300(underclocked) Mhz memory, 45% fan speed set manually)

Temps solo - 60C (Max with no AC) 56C (max with AC)
Temps for multiple GPU, with a fan blowing in between the cards - 66C max - This is the hottest
Hashes per second - 370 MH/S completely stock

Overclocking, I was able to get a pretty big boost around 450 MH/S but that was at pretty risky settings that I would not advise running

Asus Direct CU II HD 6970 - it runs a mild 940/1375 overclock on stock voltages easily. Card remains completely stable for gaming or whatever. Temps stay at or below 85C with fan at 80%. Could probably be pushed further, especially if it wer run in an open case, but I like to keep the fan noise down.

You can use Asus SmartDoctor to change the voltages if you want to go all the way.

Main problem with it is that the card takes 3 slots (!), so don't plan on using more than three of them without extenders.

I have 6 Sapphire 6970 and 2 HIS 6970. I like the Sapphire better because one of the HIS runs at higher temp.
I am currently running them at 960 MHz Core, and 340 Mhz Mem, getting a little over 400Mhash/s. The temperature range is 65-78C in a closed case 3 card machine.

The PCB manufacturer doesn't produce the GPU. All the GPUs will perform roughly the same within the luck tolerance of binned chips. You should not look by manufacturer but by card design to the one that has the best cooling solution to give you a better chance at a higher overclock (or I believe reference has voltage unlocked and you can add custom cooling to it). As suggested the CU II has a nice profile.

What did you use to underclock the mem on the 6970? I run Ubuntu for mining, but my system is setup for dual boot with win7

I used MSI Afterburner (windows)

If you haven't tried it, don't forget to change/add to your afterburner.cfg:


Everyone seems to mention it's as easy as adding the eula portion and setting unofficialoverclocking mode = 1, but that never works for me.

After you add these lines, you can lower clock, close msi afterburner and reopen, lower it again, close reopen and keep doing this. MSI Afterburner doesn't allow you to lower the clocks too far without having to close the program first.

MSI Lightning is the best 6970 to buy.

65c

Core 1000
Mem 365

430 MH/s

Sweet!!!

Sapphire by far makes the best reference cards. But best OC performance comes from cards with non-reference design cooling system