Topic: Sapphire 7950 Zcash mining questions. (Read 243 times)

Good to know mate

What you said got me thinking, and I did a Google search with "Monica", "Tahiti", "7950", and I found some very interesting info on the cards. Apparently these were never released for sale, they were given to video game developers to work with before the actual 7950s came out. I called the guy I got them from, and he confirmed that they did in fact come from a video game developer. Since the cost was almost nothing for these, they aren't really that bad a deal, since they do 170 apiece. I checked with my Killawatt meter, and the Dell PC with 2 of these cards is only pulling 270W total. I'm just going to wait till the rest of the cards come, and subtract 270 from the number after I add the 3rd card to get the per card wattage amount, it's not worth it to me to take it apart to find out at the moment, but it's definitely under 125w apiece, so that would appear to make them more efficient at Zcash then the actual 7950 (If you get them for almost free as I did) I see a 12 card rig setup coming up in the future pretty soon here. Thanks for the tip. I was driving myself crazy trying to do something that wasn't even possible, or necessary.

What you have there is a cut down pre-release version of the 7950.  You can enable most of the compute units with a real 7950 BIOS (since it is technically Tahiti), but it won't be able to sustain 200 sol/s before it throttles down to about 180-190 after it reaches temp.

The sticker on the back does say Monica, and the device manager says Tahiti. I'm not sure how to check OpenCL, but when Claymore starts up it says 12 compute units for each of the cards (I'd imagine this is the number you were looking for, but correct me if I'm wrong) Sounds like you've seen these before. Any info would be appreciated. Thanks alot.

Do these cards have [Monica] on the model #?

If so, how many compute units does OpenCL report?

     A little update for you. I was getting 4-5% rejected shares over the night so I tweaked the card a little bit. Set it to 1200/4000, and set the power down to 0% (had it at 4). Reject rate went way down. It's run for an hour so far and I'm at 850 shares, with 2 rejects. One of the rejects doesn't even really count because for some reason the first share every time the miner starts is rejected. (I don't care, I can deal with that, I'm not OCD) Hashrate went down from 173 to 171, but the reject rate going to basically nothing more then makes up for that. Going to bring in the second card later today, and I'll see where I'm at then. Wish me luck. Hoping to squeeze an extra 10% out of that one since it isn't doing the display, which would put it at 189-190. We'll see.

     Alright, here's an update. Friday night I tried the values suggested, and they were giving me considerably lower numbers then I was getting with my values and the Trixx program. It seemed pretty linear, the higher the overclock, and memory speed, the higher the hashrate. I tried a couple overclocking guides, but I couldn't get it past 164-165, and everything was glitchy as hell to get it up there. My rig restarted a hundred times while I was messing with it, and half the times the settings would all revert. At a few points the rig didn't seem like it was going to come back on. Then to end it off, at 2:00am when I was tired and not thinking clearly, it came back on after restarting, and one of the AMD cards wasn't showing up. I messed with it and reseated cables, but it wouldn't come back. I just went to bed at that point before I screwed anything else up. In the morning, after my 3rd cup of coffee, I came back, and got it right back up. (I had to shut off BOTH power supplies, and let them drain, then restart. Really stupid problem.)
     Ok, so Saturday I was getting really tired of my whole rig (With 3 1080tis) going down while I messed with these cards, and I remembered that somebody had offered me an "old server". I wasn't really interested when they offered, but I thought I'd take a look with my current situation. Fortunately, it was an upper mid range Dell i5, with 4gb ram, Windows 7 Pro, and 4 GPU ports. Perfect. So, I had to nix the case, as it was too small, and deinstall a bunch of software, and install my own. So, on this system, the Trixx program looks different, but this version isn't glitchy. I was able change the settings alot more, and usually if anything happened, it would be the hashrate on Claymore went down to 0, or had massive errors, rather then the whole system freezing up or restarting. I was getting way too many, errors, and I remembered to check the driver, so I looked, and it was the wrong one. (I had the right one on the GPU rig, just screwed up when I started messing with the Dell) So, I removed the incorrect driver, and installed the one Claymore suggests, and most of the errors went away.
     Sunday morning, now that the errors were gone, I figured I could try to overclock some more, so I went back in, and redid the overclocking, and ended up getting it up to 1210 clock, and 4000 again on the Memory power +4%. I might have to move the clock down to 1200, it seemed to have less rejects, but I'm just going to leave it alone for awhile and see how it does over time (After a half hour it's at 4%) It's doing 172-173hs with it set like this. It's lower then what other people get, but I'm hoping since it's doing the video also (no option in bios to use the integrated video if a video card is installed) that the next card I add (which is still in my main rig, just not overclocking) will get 10% more hashes which would bring me to the low end of what other people are getting. That might be the most I can get without doing one of these boot strap, tuned driver things I was reading about. The cards are a lower end version with the one fan. If they aren't overclocked, the clock speed is like 708, so getting them up to 1210 is probably as much as you can expect. I'm going to read up on the tuned drivers, and it looks like the Trixx program is really stable now, so I should be able to set each card separately at the very least, so I maybe can make some more gains with that as well.  
     When I make any additional progress, I'll let you know. Thank you, I appreciate all the assistance

No problem.  Hope it all goes well for you.  I'll just reiterate once more about the drivers.  You can try to just go with current drivers and you might get lucky.  But that would be the first place I look if there is funkiness... just read claymore's first post about drivers and you should be able to get it.

Thank you. I'll give this a try this afternoon., and I'll let you know how it goes. I appreciate the help.

My 7950 was mining at 250hs on equihash, almost 500h/s on cryptonigth and if you mine ethash(pirl, ella, not eth) you should get 20mhs. Maybe your problem is your drivers, you put those GPUs on a RX rig?

Howdy friend.

I used 7950's in a 4-GPU rig for several months before upgrading to 10-Series NVIDIA cards.  The 7950's were great on Zcash and that's mainly what I mined.  

I consistently got around 225-250 and I was using pre-overclocked boards i.e. premium boards such as the Vapor-X and Sapphire OC models.  I considered myself lucky to pick them up in the $80 range.  Congrats to you for getting them for free it sounds like!

Come to think of it... I think I used Claymore's mining software and probably set the core/mem to something like 1000/1500.  let me look...  Here we go:


So you can see there I altered core clocks but used default mem clock.  OH... But you have to have the right drivers when doing this on claymore software or you won't actually be able to adjust core clock and it might be all over the place.

I was using 12.2 Claymore Zcahs AMD GPU miner.  Again, this was nearly a year ago.  I did read some new releases but I also saw people posting that they reverted to older versions of the software because of various issues.

Always be careful when trying new mining software.  Sometimes bad things can happen.  

hth

I pay just under .10 for electric. I'm thinking if I get 10 more of them as planned, I'm can use 8 of them to start a 12-16 gpu rig and sell the other 2-4 twords better cards, and then selling them out of the rig one at a time to buy better cards with the proceeds  (thinking 470s maybe).

Where do you live? Some 7950s are good but only if you have cheap electricity rates. By cheap this should be below $0.10. Otherwise, you would probably be consuming more electricity to generate coins that are worth less. You may be better off reselling the 7950s.

Please, format your post a little better, it looks like a wall of text which is almost impossible to read, you'll get more responses that way.

To answer your question now, if what you've read is true, it could be the following ways to accomplish it. Either install a custom BIOS, if there is one for HD7950, I know there are for the newer RX ones at least. Another way could be by unlocking the voltage on your graphics card plus enabling excessive overclock (That exceeds the limits the manufacturer has set).

Hi. Hoping someone could help me out. A friend of mine from a recycling center is hooking me up with some Sapphire 7950 cards. He sent me 2 to test first, and I put them into my rig which had 2 spots left open in it, and after reading up, it sounded like Zcash was the best match for them, so I got it mining with Awesome Miner on Slushpool. At first I was only getting 89 h/s on each card, so I wanted to overclock them. Unfortunately MSI Afterburner seems to have all the overclocking options inoperative, even after enabling it all in the menu. So for overclocking I had to download this program called Sapphire Trixx. The program makes the computer really unstable though. I found if when I start the computer, if I stop the mining process for  the AMD profile right away, and go into the Trixx program, I can select the program I saved, and apply it to the AMD cards one at a time, and then close the program, and everything should be fine. I got each card up to 164 h/s this way, and it's been running a few days. I'm reading posts from the last year with people reporting hashrates almost double that though. What's the secret? I had whatever default driver first, then I installed the latest one, and saw no difference. It's really hard to experiment with settings with that Trixx program, each time you hit the cursor over one click the whole screen flashes black and then comes back, and the AMD's arent even doing the video. Sometimes it doesn't come back, and you have to reboot manually. Really flakey. I have the clocks speed set to 1050, and memory 4000, when I had the first card in there I had it higher, but the second one didn't like it, so I set them both down lower so they would match. Power is set to +9%. Getting 2X the hashrate would be key, so I was hoping someone could help me out. Thank you in advance.