Mine Gigabyte GTX 750 Ti (N75TOC-2GI)
It's installed inside a regular closed case desktop directly at the PCI-E x16 slot.
I spent the whole night testing it with Cudaminer and EVGA Precision X.1) Chrome Trick
First, I tested the "Chrome trick" with several other software.
No OC e no parameters on Cudaminer.
Below the results:
As seen, the best average rates that you will achieve is 243KHs for cudaminer 32 bits version and 258KHs for the 64 bits version.
As Chrome proved to be the best option (Google Earth is a "heavy" program to be running in the background), I decided to use only it for further tests.
The following tests were performed with Chrome running (doesn't need to be maximized).2) Cudaminer Tunning
The minimum set of parameters for Cudaminer give some real improvement is this: -l T5x24 -i 0 -C 1
With it I got 264KHs in both 32 and 64 bits version.
So, I tried almost all possible combinations of the most usual parameters. Here's my conclusion:
- Changing T5x24 to T10x24 makes no difference.
- Changing C1 to C2 gives you around 1KHs more.
- Adding -m1 gives you around 1KHs more.
Thus, the following set is recommended for a average rate of 266KHs: -l T5x24 -i 0 -C 2 -m 1
You can gain another 10KHs adding the -H1 parameter. I achieved around 275KHs with it (-l T5x24 -i 0 -C 2 -m 1 -H 1).
However, it will make use of your CPU together with the GPU, which will cause greater temperature and, specially, noise.
Using -H1 my CPU remained constantly above 60ºC and the fan was very loud.
I don't have a Kill-A-Watt to evaluate precisely, but, I can imagine that the KHs gained will not pay the extra KW.
Using -H2 makes no sense because its the default value and brings no gain.3) Overclock
I wasn't so thorough in this part as previous ones (I'm without sleep and tired), but, I managed to perform some tests.
Assuming the recommended Cudaminer parameter configuration (-l T5x24 -i 0 -C 2 -m 1), I could achieve around 300KHs with the following EVGA Precision X profile:
- GPU +135
- MEM +700
- Power Target 100%
GPU temperature remained at 58ºC and fan speed at 70%. Very stable and quiet OC.
I think much more than that cannot be "power effective".
Some more aggressive values crashed the GPU.
Will research more OC options next days.