Topic: Powercolor AX6870X2 @ Newegg for $450 (Read 6775 times)

these cards will only allow you to lower memory by 100 less than the gpu clock speed.
since you are on linux, you can flash the bios and should be able to run fine with lower memory speeds.  if you flash the bios and try to run under windows, the drivers will crash.

While I don't have these specific cards, I had the same memory underclocking issues with my 5870's as you described above until I updated to driver version 11.6. Not sure what version you are running but thought it might be of use..

I have 12 PowerColor 6870x2 and I wanted to build "that dense rig" with 4x card (hence, 8 GPU on board) multiple times. But - No luck on following issues:

1) Underclocking memory: I didn't even manage to get down from 1050. aticonfig --odsc=920,820 doesn't work. This is what all of the GPUs show afterwards:

Adapter 1 - AMD Radeon HD 6800 Series
                            Core (MHz)    Memory (MHz)
           Current Clocks :    920           1050
             Current Peak :    920           820
  Configurable Peak Range : [775-1000]     [1050-1250]
                 GPU load :    99%

2) 4 Cards simultaneously: Booting with 4 cards is no problem (ST1500W SilverStone PSU installed), and they all show up in aticonfig (Linux distro). But as soon as X is starting, it bails out with a Segmentation fault. If I pull out one card and install a 5850, or a 6970, I've got 7 happily mining GPU's. The 8th one fails down the whole system. I don't believe it's a power issue or a hardware issue at all, as all of the barrier values aren't reached at all.

3) Powering clocks on anything higher than 920: Currently, thats the maximum clock frequency the cards stay stable on. Raising it to 930 kills the cards at last; they freeze at a random time afterwards. In the end, the cards stay below 300 MH/s with these settings (at 294).

I bought these cards on the better price ratio opposed to the 6990, and because of the fact almost no supplier can deliver 6990s at the moment, at least in germany. But at the moment I tend back on waiting for the (more expensive) 6990 cards, for the sake of getting at least 2,5 GH/s out of one box.

If anyone have better experience and conclusions on this device, I'd be happy to hear and share some wisdom about it.

Addressed to me, from PowerColor tech support:

"I did a  bit of research and was able to confirm what XXXXX mentioned earlier (see my prior quote from powercolor tech support). They don't allow this because it'll compromise the card's performance too much. In your situation it's practically irrelevant because you don't need bandwidth, all you need is GPU power, but unfortunately it's not something that can be done.
 
In my experience with other cards, lowering (or increasing for that matter) memory clocks has a very small effect on overall card temperatures. That's the main premise behind the popular internet argument that memory module coolers are useless and do nothing to improve overclocking capabilities. So I apologize that you're not able to lower the memory clock speeds, but even if you could there would be no reason to expect any kind of drastic drop in temperature.
 
Let me know if you have any other questions."

Whether or not the manufacturers know we exist is irrelevant. They are not the middleman taking part in the price gouging of radeon cards, or at least those cards which are desirable to us miners. A

As they say, laissez faire.

not sure what your tangent is...

my comment is related to many posts that discuss economics of bitcoin mining and how they effect video card sales.  some posters say that mining is creating a noticeable increase in video card sales.  it's been discussed and shown that's not he case.

me posting the question from the manufacturer pokes fun at those discussions to show that yes, the manufacturers do not notice bitcoin mining.

first of all, manufacturers don't make the video cards to tailor it to miners. second, there's no association of mining and memory underclocking. yes, a lot of people on this forum know that you're suppose to underclock the memory to save power and lower temps, but it's not automatic knowledge that you're suppose to do that, and people that barely heard of mining wouldn't even think about doing something like this. and third, you're not suppose to change any of the stock specs that shipped with the video card. this is something that's considered voiding your warranty. at least if you're going to do that, don't let manufacturers know. of course, they do know that a lot of people overclock their cards, but just don't openly admit to it.

After leaving an appropriate review on newegg.com for this product  (you can see it, review by Canary), the manufacturer responded and offered to help.

Hugo had 2 questions for me.  1st is whether the card crashes. obviously no.

second (regarding lowering memory speed):

PowerColor: "Why would you want to do that?"

So, I emailed Mr. Hugo my previous correspondence with PowerColor and answered his questions.  Let's see if he can help.

But that's not the point.

The point here is that for all you who sometimes think that bitcoin mining is somehow "showing up" on the radar of Radeon manufacturers or that bitcoin mining is making the video card sales go though the roof:

sorry, they have no clue...  we don't exist.

Thanks for the info!  I might be forced into linux after all...

TO clarify the people asking about flashing 6870's bios and linux: it works fine. All 11 of my 6870's (Stupid hard to get 5830's here in soviet canukistan) are bios flashed and chomp along fine in linux, to increase the volts and fan curve and max OC. I did most of this before the new catalyst came out, letting you OC past bios limits.

So, the problem with the bios flash (at least for single 6870's, so I assume the 6870X2), is very much the windows driver, not the flash itself.

Side note, I have never dealt with NCIX US, but the canadian side I have a few times, and they are legit. No problems with hardware to know how good they are about RMA, though.

Saw that deal as well. Not sure why they had it listed at $200 for so long, obviously nobody would pay that much for a 6870 single GPU card which is why it sat there for weeks. Looks like they wised up and somebody got a great buy.

I saw that sitting there for awhile at 200. 127 is a wicked good deal that's like getting a 5830.

Yikes!!

I've been keeping an eye on this:

http://www.newegg.com/Product/Product.aspx?Item=N82E16814131383R

it was pricey... I last checked a few hours ago and it was still over 200 dollars...

just checked now and wow! someone snatched it for 127... nice deal...

couldn't tell you... don't have a 5970. but i suspect it's lower. because youcan down-cklock memory on 5970, thus attaining lower temps whenre the fan can be set to lower setting.  this particular ax6870x2 won't let you reduce memory by much, so it does run hotter and thus louder.  i have to keep fan at 80% .  However, 6990 is obviously louder than all of these...
for me though, noise isn't an issue... all miners are locked in a computer room... so i don't hear them.

How's the noise level compared to a 5970?

Yea I got 5 5850's from them as well. Took them a couple days to finally ship out the product but otherwise I had no problems with them.

yes, they are fine.  ordered a bunch of 5850s from them a while back. got them OK, took some time.

not a bad price, but with ncixus there will be a shipping charge...

so, far this card is not on par with 6990 or 5970s on Mhashes alone, but on price that's a different story...

Any experience with that merchant?

Found a the same card for 25 bucks cheaper at ncixus (http://www.ncixus.com/products/?sku=62694&vpn=AX6870X2%202GBD5-2DHG&manufacture=PowerColor&promoid=1365)

Not a great card but if your going for megahash per server this is almost in par with 6990's and 5970's and it beats them in megahash/$