Had a 7990 - got replaced with a 295x2!

hasherhasher Member Posts: 642 ✭✭✭
edited August 2016 in Mining
So, I had a bunch of 7990s left over from the litecoin mining days, and these cards came with a 3 year warranty.
With under 1 month of warranty left, one of the cards died - so went to get it claimed under warranty. They couldn't fix or replace the card, so they suggested giving me a 390X. I obviously refused and wanted something with equal or better power. A few days later, they called me back and gave me a brand new HIS 295x2 as a replacement. For free.

The 7990 alone was doing close to 40MH in Claymore (almost 20MH per GPU)

The 295x2? Lol... overclocked to the max, it hit almost 69MH! (~34.5MH per GPU) but the best thing about this card is the water cooling. I'm mining at the speed mentioned above with a cool 66C.

Its a shame these cards were so ridiculously expensive when they were launched, but if anyone can pick them up used, go and do it. I really want to see someone make a 4x 295x2 rig :)


  • newmznewmz AustraliaMember Posts: 299 ✭✭✭
    Isn't it sucking power like you need your own nuclear reactor? imagine the power needed for four of them....
  • hasherhasher Member Posts: 642 ✭✭✭
    I'm not sure what its consuming, but I assume its going to be the around the same as the 7990. I used to run 4x7990 rigs with 2 x 1200W PSUs. Worked like a charm.
  • stoonstoon Member Posts: 337 ✭✭✭
    That's why people aren't using the dual mining cards anymore. They consume too much power for what they produce in hash rate and they also produce a ton of heat, this of course compares to the 480, 470's. But your right, they are monsters for a single PCI slot and if you can get a cheap used one then maybe it might be worth it.
  • bbcoinbbcoin Member Posts: 377 ✭✭✭
    edited August 2016
    475w you should see around 520 at the wall. Dual GPU are good for mining. I would even say that's exactly why they were created.

    7990 was too loud and run hot most or the time.

    Rx480 undervolted will give better efficiency but 295x2 is way better than any 370, 380 or 390

    Don't believe any of the fantasy with 600+ watts.
  • kn28kn28 Member Posts: 2
    I myself have a 2x295x2 rig, with about 400 :# $ (used) for each card, and I think it works really well.

    First, it is not that power inefficient. You see, a 2x295x2 rig is the same 4 x 290x. I can use a 1200W psu to run 2 295x2, but cannot run 4 290 with the same psu (even my pcie cable is not enough).

    Second, since 295 x 2 is water cooling, it cools very well. Instead of 7990, we do not need anything special for cooling. Currently I just plug the two cards directly into the motherboard without a riser, and close the enclosure, since I put my pc in my office to get free electricity :#. It cools very well (never goes above 70C).
  • nathannnathann Member Posts: 72
    What settings do you guys run with your 295x2's?
    I run currently, -45mv, 1040 core with stock mem.
  • hasherhasher Member Posts: 642 ✭✭✭
    For some reason, afterburner won't let me adjust voltage on my HIS 295x2, so i'm currently running at 1170/1500 with stock voltage, and getting 66.48MH (~33.24 per GPU) @ 65C with claymore's miner.

    I could push it higher, but I don't wanna stress the card out too much. Its been happily running for 2 days now at the current settings.

    @nathann how did you undervolt your card?
  • hasherhasher Member Posts: 642 ✭✭✭
    kn28 said:

    I can use a 1200W psu to run 2 295x2, but cannot run 4 290 with the same psu (even my pcie cable is not enough).

    Thats strange.. I have an ethOS rig running with 4 x 290's (heavily overclocked) running on a single Corsair AX1200i PSU and its been running great. PSU fan hardly turns on, so i'm guessing its not consuming anywhere near 1200W. I think even a 1000W PSU could run the entire rig without issues..
  • nathannnathann Member Posts: 72
    edited August 2016
    hasher said:

    @nathann how did you undervolt your card?

    Just using afterburner, mines a xfx model though.
    I only undervolt because mine thermal throttles like a mf.
    Going to try get better airflow this week and can hopefully squeeze out a few more MH/s
Sign In or Register to comment.