Quote from: madman1980 on March 01, 2014, 06:23:10 AM

Quote from: cvax on March 01, 2014, 05:11:22 AM

Quote from: madman1980 on March 01, 2014, 04:58:46 AM

Hey guys,
  Am new here, and new to mining with Nvidia cards. I've been following this thread for the past week, finally got my hands on a few of the 750Ti cards last night. Picked up 3 different brands, but have only had a chance to tinker with the MSI twin frozr (no pcie plug) so far. I am definitely no expert, and am learning cudaminer as I go, but wanted to share my experience so far:

  I've only run one card at a time so far. Biostar H81S2 mobo, 4gb ram 750w psu. and mostly using auto-tune, as I dont understand the blocks and warps yet..
System idle = 42.2W (per killawatt meter)
gpu = +0, mem= +0, load @99% = 114W. hashrate 268 kh/s T5x19
gpu = +0, mem +300, hashrate 252kh/s (T230x1. this may have been a bad setting by auto-tune, i'm not sure. i initally was trying gpu and mem clocks others were reporting, and was getting alot of instant artifacting, or 'rapid scrolling' error. so i left it at that, and moved on to doing the TDP raising bios mod.

  With TDP bios mod:

gpu = +0, mem= +0, hashrate 272khs, T10x24, gpu utilization 75% (?), and system load increased to 124W (from 114W)
gpu = +0, mem= +300, hashrate 291khs, T10x24, system load = 130Watts.

  This last setting was stable for 6+ hrs while I was at work today. I have tried, briefly, with higher gpu and mem clocks, and highest i've hit was ~322khs. but i need to keep testing for stability, as i was getting errors along the way. Interestingly, the bios mod has definitely increased power draw, and has allowed near 300khs with a modest +300 mem overclock. I have seen others on this thread with much higher clocks at this speed. Christian, are you using a modified bios on your 750 Ti? I feel there is more there. Also, after the bios mod, the power % on Precision X drops to 75%. I dont understand this, or if it may be reporting it incorrectly.
   I'll continue seeing how far i can push this card. I am concerned about the scalability issues others are having, and will assess this as well, when i have time to add other cards (hopefully tonight). Will keep you guys posted on my findings.

Hi madman,

I believe your findings are in line with mine. I would say try the non-BIOS mod +300 mem overclock again with the same T10x24. My results yielded no additional hashrate with the power mod, but increased power consumption.

Re-ran it on stock bios, +300 mem, T10x24, and at 268-269khs, unchanged from stock clock settings. Another note, this was on the pci-e 16x slot, no riser. I just tried the card on 2 different powered riser cables (ribbon and usb), and seeing reduced hash rate ~255khs, and reduced system wattage on the killawatt meter to around 114W, even with the above mem +300 overclock. Huh

Believe risers may be expected to reduce some hashing. Did you use the riser in PCI-E 1x slots or 16x to 16x? I am about to try my risers as well. What 69charger said for T5x24 being optimum I can confirm that as I just finished profiling my 8 Zotac GTX 750 Ti's.

For anyone curious here are the results of my 8 cards. Watts are system wide.
165w idle @ stock and overclocked
Overclock = +135 core +600 mem

Code:

Average Zotac GTX 750 Ti:
Stock Scrypt: 261.9kh/s
Stock Scrypt-Jane: 3.07375kh/s
Stock Keccak: 22000kh/s
OC Scrypt: 293kh/s
OC Scrypt-Jane: 3.415 kh/s
OC Keccak: 22000kh/s

Card 1:
Stock Scrypt: 260 kh/s @ 228w
Stock Scrypt-Jane: 3 kh/s @ 220w
OC Scrypt: 288 kh/s @ 230w
OC Scrypt-Jane: 3.35 kh/s @ 223w

Card 2:
Stock Scrypt: 262 kh/s @ 228w
Stock Scrypt-Jane: 3.12 kh/s @ 213w
OC Scrypt: 295 kh/s @ 230w
OC Scrypt-Jane: 3.45 kh/s @ 220w

Card 3:
Stock Scrypt: 261.5kh/s @ 222w
Stock Scrypt-Jane: 3.06kh/s @ 210w
Stock Keccak: 21570 kh/s @ 180w
OC Scrypt: 292kh/s @ 225w
OC Scrypt-Jane: 3.41 kh/s @ 215w
OC Keccak: 22088 kh/s @ 180w

Card 4:
Stock Scrypt: 264kh/s @ 228w
Stock Scrypt-Jane: 3.12kh/s @ 213w
Stock Keccak: 22296kh/s @ 181w
OC Scrypt: 300kh/s @ 230w
OC Scrypt-Jane: 3.45 kh/s @ 218w
OC Keccak: 22000kh/s @ 182w

Card 5:
Stock Scrypt: 263kh/s @ 228w
Stock Scrypt-Jane: 3.06kh/s @ 212w
Stock Keccak: 21557kh/s @ 182w
OC Scrypt: 300kh/s @ 230w
OC Scrypt-Jane: 3.44 kh/s @ 218w
OC Keccak: 22557kh/s @ 185w

Card 6:
Stock Scrypt: 263kh/s @ 228w
Stock Scrypt-Jane: 3.10kh/s @ 216w
Stock Keccak: 21822kh/s @ 181w
OC Scrypt: 295kh/s @ 231w
OC Scrypt-Jane: 3.44 kh/s @ 222w
OC Keccak: 21903kh/s @ 183w

Card 7:
Stock Scrypt: 261kh/s @ 228w
Stock Scrypt-Jane: 3.06kh/s @ 218w
Stock Keccak: 23054kh/s @ 185w
OC Scrypt: 285-290kh/s @ 230w
OC Scrypt-Jane: 3.41 kh/s @ 223w
OC Keccak: 23029kh/s @ 183w

Card 8:
Stock Scrypt: 261kh/s @ 227w
Stock Scrypt-Jane: 3.07kh/s @ 214w
Stock Keccak: 22503kh/s @ 185w
OC Scrypt: 285-290kh/s @ 228w
OC Scrypt-Jane: 3.37 kh/s @ 220w
OC Keccak: 22502kh/s @ 185w

Edit: My keccak numbers are way low with only 20% GPU usage apparently. Bad settings. They are now up around 144000kh/s.