Vertcoin Settings, Optimal Thread Concurrency, and HW Errors

Not surprisingly, given the current prices [which I predicted about ten days ago!] people are starting to pull their hair out when trying to tune their configuration files to work with Vertcoin (VTC). In fact, I have been one of those people, so naturally I decided it would be best to adapt my previous work to get things running with the new version of cgminer.exe. This round, I have two different versions of the batch file to run, one for Radeon R9 290 and R9 290X, and one for earlier GPUs.

You can download my test scripts from Dropbox.

The key items to change before running are all in the two following files. Note that I'm using the custom version of cgminer found here, as opposed to the slightly different version of cgminer named vertminer found here. I don't know if there's really much of a difference, but I started tuning on the first version (linked from Vertcoin.com) before hearing about Vertminer (linked from Vertcoin.org -- go figure). It sounds like some people are getting fewer HW errors with Vertminer, but at least initially I lost about 50 KHash on my 3x7950 rig so I'm staying with the first miner for now. Anyway, the main files to look at are:

thread-concurrency-test.bat
thread-concurrency-test-r9version.bat

As you can hopefully guess, the r9version is for R9 290/290X (it's not necessary on R9 270/280X as those are basically just rebranded 7000-series hardware); technically this version should work for any GPU, but I've found it can be a bit... flaky. Basically every few restarts of cgminer.exe, one or more GPUs will stop working properly and you'll need to reboot the PC. So hopefully we can get a fixed EXE for R9 systems sooner rather than later (and if you have such an EXE, please email me).

Here's the short list of settings to change, and below I'll have some recommendations based on running these scripts on my own hardware. All of the settings below are for both versions, except "roundtime" which comes from the non-R9 version, and "shares" which comes from the non-R9 batch file:

Starting thread concurrency. Note that if file "CURRENTTC.TXT" exists, that will override this value!
set threadconcurrency=6000

GPU engine and core clock(s). If you want to set different clocks, use commas with quotation marks around the set (e.g. gpuclock="1000,975,950" for three GPUs)
set gpuclock=900
set memclock=1450

GPU fan speed range (can use multiple sets with quotes as above if needed)
set gpufan=50-95

GPU voltage tends to only work on older GPUs (5000 and 6000 series, and some 7000)
set gpuvolt=1.071

PowerTune setting can specify for multiple GPUs with quotes; only supported on 6000 and newer GPUs.
set gpupowertune=10

Intensity setting for mining
set intensity=18

Number of GPU threads
set gputhreads=1

Number of shares to mine on each TC setting before moving on. If you have a high share difficulty, lower values may be useful.
set shares=60

How much to increment thread concurrency each round -- for Vertcoin mining, I've found steps of as small as 1 to be potentially useful!
set threadincrement=4

Number of seconds to mine on each round.
set roundtime=300

Number of GPUs being used -- the output includes performance from each GPU on a separate line, hence the need for this setting.
set numgpus=3

The instructions for using the batch files are pretty simple: extract the above files into your cgminer-vertcoin folder, then edit the appropriate batch file and change the above settings as appropriate. In general, that means you should tweaks the GPU clocks, the starting thread concurrency, and potentially the intensity and gputhreads settings. The number of shares and/or roundtime can be adjusted; I'd generally recommend increasing these values rather than going any lower, as the more time you spend hashing at each TC the better the overall estimate will be.

There are just a few disclaimers before I wrap up. First, I take no responsibility if any of these files mess up your PC or kill your GPU. They should be safe, but you never know. Second, the R9 version seems to be a bit less stable, and it seems to cause the GPU drivers to crash, especially in multi-GPU systems. You might have better luck than I did, of course. Finally, every system is different, so what works really well on one PC may not work well at all on another -- and I've found in general that it's very difficult to find a setting where you get optimal hash rates without getting any HW errors; mostly, I just try to keep HW errors below 1%.

Donations as always are (very!) welcome. I'd appreciate just an hour or so of your mining time if you don't mine, or you can donate to any of the following addresses:

VTC:  VaNuRCj73JVAwR1YMnt8CXaqoiPgykiMTk
BTC:  153qS9Ze32hnV3fwirZLWNka4wBAowc21E
LTC:  LfCLyykrNFftzpdWejR73hf478ZtBzQ9jE
DOGE: DD9iTWf8diPkvKdB8roPJepTyp6BGVQtct

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Here are settings that I have found to be stable with the noted hash rates. I'm still trying to nail down optimal settings on many of the systems, as well as finding something that works well for R9 290/290X. I'll update my list as appropriate.

Radeon HD 7970 (R9 280X) (using vertminer.exe):
GPU clock: 1050-1140
RAM clock: 1500-1800
Thread Concurrency: 8192
GPU Threads: 1
Intensity: 13
Hash Rate: 290-320 KHash/sec

Radeon HD 7950:
GPU clock: 950-1000
RAM clock: 1425-1500
Thread Concurrency: 16040
GPU Threads: 1
Intensity: 19
Hash Rate: 270-290 KHash/sec

Radeon HD 6970:
GPU clock: 925
RAM clock: 1400
Thread Concurrency: 8000
GPU Threads: 1
Intensity: 18
Hash Rate: 230-250 KHash/sec

Radeon HD 6950:
GPU clock: 875
RAM clock: 1250
Thread Concurrency: 6000
GPU Threads: 1
Intensity: 18
Hash Rate: 210-230 KHash/sec

Radeon HD 5870:
GPU clock: 925
RAM clock: 1150
Thread Concurrency: 5688
GPU Threads: 1
Intensity: 18
Hash Rate: 200-220 KHash/sec

Radeon HD 5850:
GPU clock: 850-900
RAM clock: 1050-1100
Thread Concurrency: 5120
GPU Threads: 1
Intensity: 18
Hash Rate: 170-190 KHash/sec

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Again, donations are very much appreciated. And if you have some other coin you'd prefer to send, let me know!

VTC:  VaNuRCj73JVAwR1YMnt8CXaqoiPgykiMTk
BTC:  153qS9Ze32hnV3fwirZLWNka4wBAowc21E
LTC:  LfCLyykrNFftzpdWejR73hf478ZtBzQ9jE
DOGE: DD9iTWf8diPkvKdB8roPJepTyp6BGVQtct