CPU, RAM, and hard drive requirements

quantumgravityquantumgravity Member Posts: 13
I plan to build a system with six AMD R9 280s. My first question is, would it run smoother with at least one CPU core per GPU? I am planning to get an 8 core CPU. Is that overkill?

How much system RAM would be required? I was thinking 2 GB per GPU for a total of 12 GB. Is that enough?

One last question, how big of an SSD would be ideal for this system? I plan for it to be a dedicated Ether mining rig running 64-bit Ubuntu. Will I need a large amount of hard drive storage as the blockchain grows?

Comments

  • eupraxiceupraxic Member Posts: 16
    I have a couple of mining servers configured with six R9 280s each. They are using cheap AMD Sempron 145 CPUs with 4GB of RAM. It's possible that more cores or RAM would increase performance a bit, but I don't have any issues with my configuration.

    I can't comment on the expected rate of growth of the blockchain. My mining servers are diskless (with a USB flash drive to hold the DAG). The blockchain is stored on a separate server running geth. Of course, if you plan to run a full node on each mining server you will need room to store the blockchain (currently around 150MB) along with at least 2-3 generations of the DAG (about 1GB each).
  • quantumgravityquantumgravity Member Posts: 13
    Thanks for the reply. That's helpful
  • hangabershangabers Member Posts: 63
    [EDIT] I may have found my answer in your CPU/GPU choice... AMD Sempron 100 (AM3) R9 280 (PCIE3.0)... haven't seen many AM3 boards with PCIE3.0... opinions are still welcome[]

    Hey I saw this post and it really got me thinking about the rig I wish to build.

    Wondering if I could get some opinions on my proposed hardware.
    First off, I have an Asus M4A79XTD lying around that I'd love to put to use. But I'm worried it might be a bit old.
    It has 4 PCIE slots, and 2 PCI slots (I'm pretty sure I can't use the PCI slots for mining), and supports up to 16GB of memory; so it would presumably be great for GPU mining back in 2010.
    However, It's DDR3, PCIE2.0 and I have no idea as to it's efficiency/power use/power management. (More research needed)

    That said, if I can use the motherboard, I'd probably start with a cheap low end CPU.
    Sempron 1xx sounds like a great choice.

    4 R9 270x (280/290/295/295x[I doubt I'll find a cheap 295x] whichever i find first) and I can add and upgrade the cards as I need
    (4 R9 270x give more power on paper than 2 R9 290 for roughly the same price, but 2 R9 290s leave space to upgrade more) <--still deciding, if I can use mismatched GPUs then I get more incremental upgrade options)

    8GB DDR3 memory

    64GB SSD

    Ubuntu
    ....

    Haven't even looked at power use yet. But that can come later.

    I appreciate any help

    Thanks fellow Ethereans


  • eupraxiceupraxic Member Posts: 16
    @hangabers that sounds like a good build for a mining server. DDR3 memory and PCIe 2.0 slots are fine. I have one motherboard that has a mix of PCIe 2.0 and PCIe 3.0 slots and I don't notice a difference in mining performance.

    You will need to use risers if you plan to install 4 gpus.

    Mismatched gpus work fine. One of my servers has a mix of AMD R9 270 and 280x gpus.

    You can probably just install ubuntu on a USB flash drive and skip the SSD if you want to save a few more $$ but the extra space on the SSD would be convenient.
  • jzenjzen Member Posts: 49
    @eupraxic, which OS are your using?
  • eupraxiceupraxic Member Posts: 16
    I am running Ubuntu 14.04.2 LTS on my geth server and all my ethminer servers.
  • hangabershangabers Member Posts: 63
    edited June 2015
    @eupraxic hey man thx for the USB flash tip, completely forgot about that little fact. And ya, risers for life haha. Thankfully, the nice thing about heavy GPUs, is they are powered, which means I don't have to use powered risers.

    But ya update, I crunched some numbers and figured out that starting with
    1 R9 295x2 & 3 R9 270x will give me a rough estimated hash rate of 95MH while only burning roughly like 1200 W

    This initial setup keeps me on budget both short and long term, gives me a hefty hash rate upfront while giving me plenty of room and incentive to slowly change out my 270Xs with 295X2s. Each upgrade bumps up the MHs by about 35MHs each time.

    Also, check out the AMD Athlon II X4 610E runs about 45W like your superon, but is also quad core.

    Next step is cooling...

    this thing may run in my room, I really don't want a jet engine, but I also don't want my cards to burn up.

    Also also for those looking in

    The R9 270x squeezes the most out of the dollars spent and is light on energy requirements.

    The R9 280x gives you a big MH boost over the 270x for not much more entry price, but it's eats more power

    Get the R9 290x if you can find it as cheap as the 280x, the power consumption isn't much more.

    But the pound for pound winner, and frankly best dollar spent (long+short) to MH power is the R9 295x2. Its power efficiency ratio basically like the 270x with double power of a 290x on one card. Dollar wise, it's steep, but it's worth it.


    Don't even bother with the R9 285, it is just a last gen card with the newest architecture, but without the hashrate gains.


    Please note all of this info was simply looking at other people's results, compared with on paper specs, using other people's efficiency and mining calcs to make a "best guess". Results obviously may vary.

    Post edited by hangabers on
  • eupraxiceupraxic Member Posts: 16
    @hangabers nice analysis of the gpu choices. And, thanks for the tip on the AMD Athlon cpu. I'll keep it in mind for my next build.
  • rpmxrpmx Member Posts: 21
    edited June 2015
    I am planning on building a mining rig as well, something I've never done before, and would also appreciate your opinions.

    For a little background, I'm planning on using this as a main computer, so I'm buying a case, and the mining will be done using 2 x R9 290s.

    I want the display to be plugged into the motherboard, using the integrated graphics. I've done some google (and reddit) searches on this topic, and a lot of people who have tried to set up their system the same way have said that they needed to use dummy plugs in order for the OS to power on the GPUs.

    Most of these search results are from mid-2014 at the latest, which could mean that things have changed for the better in the meantime (thanks to newer drivers or something like that). However, in case they haven't, I want to ask if anyone here has run across problems using your graphics cards for mining, while the display was plugged into the motherboard.

    I'm also interested if there's a difference, compatibility-wise, between having an Intel vs. an AMD CPU in the system. My initial decision was to go with the Intel, thanks to better CPU performance at a similar price point, but I just came across a page on amd.com which explicitly mentions the possibility of plugging the monitor into the motherboard, with the discrete graphics remaining active, so I am wondering if maybe opting for AMD would guarantee a trouble-free experience from this point of view.

    Again, I'd appreciate any help on this topic (Lord knows, I need it!) Thanks!
  • hangabershangabers Member Posts: 63
    I'm very inexperienced, but my take is, forget intel as the increased power will do nothing for you. All you need the cpu to minimal computational tasks, from what I understand it won't factor into your hashrate. Also, perhaps the you just need to find a way to tell the os to power on the GPUs instead of using an auto sense function. I assume you can do this in Ubuntu and or in command line.
  • rpmxrpmx Member Posts: 21
    edited June 2015
    Thank you for replying.

    In the end, I bought an Intel-based motherboard a couple of days ago, partially due to the fact that it allows installing the GPUs so that there are 2 unused slots between them, which I've read should lead to easier thermal management. It was also at a nearly 50% discount. Given this opportunity, it made sense to prioritize thermals and cost, and if I'd found something similar that was AMD-based, I do think I would have gotten that.

    I really would like to use Ubuntu (or Xubuntu, which I use now), so I'll definitely try installing one of these operating systems first and see if I can do what you suggested.
  • hangabershangabers Member Posts: 63
    Ok update, So I have almost locked down 2 XFX R9 290X for a stellar price. Here's hoping I get them
    2x 4GB DDR3 1333 (8GB total)
    Sempron 145 (single core 45w)
    Roswell G1000
    P3 P4400 Kill A Watt Electricity Usage Monitor
    Ubuntu
  • DaveHDaveH Member Posts: 42
    edited July 2015
    @eupraxic I just saw your comment above and wanted to pick your brain on the mismatched GPU point with a couple of possibly silly questions. Do you need to install a driver for each different gpu? I *think* I have a second mismatched gpu up and running but a couple of oddities are causing me to wonder if its actually working:

    I have Ubuntu 14.04.2, 4670k, 8gb, 250gb SSD and R9 290x gpu up and running following this guide (http://spacience.blogspot.co.uk/2015/05/ethereum-gpu-mining-ubuntu-1404-lts.html) and getting 25-26MH/s.

    I then came across a 280x and wanted to add it in. I plugged in the 280x beside the 290x and turned the PC on. I then opened a terminal for each card and ran "ethminer -G --opencl-device 0" in one which started the 290x mining; I then ran "ethminer -G --opencl-device 1" in the other which I *think* has started the 280x but I'm not entirely certain for the following reasons:

    - the start up process for the second card indicated that it was starting a 'Hawaii' card (ie a 290X); a 280x is a 'Tahiti' card and it had been recognised as such when I began mining on my HDD with a single 280x before I switched to the current mining set up on an SSD so I expected it to say 'Tahiti';

    - the hash rate on the second card is between 20-21MH/s which seems high compared to the 290x (25-26MH/s) and the hash rate I got out of the 280x when mining with it solo on the HDD (14-15MH/s)

    Does this sound odd? Is there anyway I can confirm that the 280x is actually mining or is this second terminal showing me some kind of info about my 290x? Can I see the total hashing power of my set up somehow?

    I'm finding blocks and the PSU and GPU fans seem to be cranking so it appears to be working but the two reasons above (especially the system recognising the second card as a Hawaii) is nagging me that maybe I haven't done it right.

    Any help appreciated.
  • eupraxiceupraxic Member Posts: 16
    @DaveH It's probably fine, but there are a few things you could check.
    DaveH said:

    Do you need to install a driver for each different gpu?

    Nope. The driver will support all GPUs in your server.
    DaveH said:

    - the start up process for the second card indicated that it was starting a 'Hawaii' card (ie a 290X); a 280x is a 'Tahiti' card and it had been recognised as such when I began mining on my HDD with a single 280x before I switched to the current mining set up on an SSD so I expected it to say 'Tahiti';

    I would have expected it to say 'Tahiti' as well.
    DaveH said:

    - the hash rate on the second card is between 20-21MH/s which seems high compared to the 290x (25-26MH/s) and the hash rate I got out of the 280x when mining with it solo on the HDD (14-15MH/s)

    ethminer reports a hash rate of anywhere between 19MH/s and 25MH/s for my 280x GPUs, so that sounds like a reasonable hash rate.
    DaveH said:

    Is there anyway I can confirm that the 280x is actually mining or is this second terminal showing me some kind of info about my 290x? Can I see the total hashing power of my set up somehow?

    I don't know how to determine the total hashing power of the server other than manually adding the values reported by each ethminer instance.

    You could try any/all of the following to get more information on your cards:
    ethminer --list-devices
    lspci -v | grep VGA
    aticonfig --list-adapters

    While both cards are mining, if you run the following command, the "GPU load" should be greater than zero for both cards:
    aticonfig --adapter=all --odgc

    I suppose it's possible that your /etc/X11/xorg.conf is misconfigured. If you decide the second card isn't working, you could try rebuilding it with:
    aticonfig --adapter=all --initial -f

    Good luck!
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