1T 2T Command rate

ChrisLandin

ChrisLandin

ChrisLandin

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Hiya all, what does this 1T or 2T command rate thing mean please? Is there a better setting? Is 2T better than 1T? Will I notice a difference? Thanks
 
As above it will depend on the memory controller, not the RAM itself (a common misconception), as to whether you'll get away with it or not. Success or failure will vary with different motherboards. Might be worth trying since it does give a performance increase with multi-channel DDR2/3 systems, albeit a very small one, usually nothing more than a few percent in real world type testing. More reliable sources do not recommend 1T if you are overclocking. Since I run my RAM at stock I've got the command rate set to 1T without any problems but if your mobo / OC isn't happy with it, then it's no great loss at all. A stable OC at 2T will possibly provide more of a real world gain.
 
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My cpu is overclocked to 3.7 on 1T, i might try 2T then to see if it runs more smoothly. At the moment it passes prime and IBT no issues but feels a little laggy around the desktop and thats running windows 7
 
Basically 1T allows your IMC to address the memory every cycle and 2T every other cycle.. in reality this means that 1T is slightly faster as it can initiate tasks in memory quicker.. in the real world there is around a 5% performance difference between the two.

Often however it is better to have 2T with higher frequency and tighter memory timings over slower frequency / loss timing 1T
 
Often however it is better to have 2T with higher frequency and tighter memory timings over slower frequency / loss timing 1T
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That was my experience also when running ReaperX with very tight timings (at 2T) on my old Core 2 rig.
 
I got my 12 Gb of geil ram working at 1600 Mhz and T1 with two channels at 7-7-7-20, and one channel at 8-7-7-20 (one pair of modules didnt like CAS 7 too much).

Dont think I can ask for much better than that :). Reduce any number down to a 6 and hilarity ensues as my PC mimicks a large dead brick.
 
Yellowbeard said:
Just FYI, you can't run 2 different sets of timings on the same MOBO.
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You can on Gigabyte mobos ;)

http://img32.imageshack.us/img32/9331/img001cf.jpg

You can set different timings per each channel, the third channel doesnt work with 7-7-7-20, I only get 8 Gb detected, but when set like this all 12 Gb works. What I have is 3 sets of 4Gb kits, with one identical pair per channel. Two pairs are 1 digit apart on the serials, then the third pair is a completely different serial :(

It just started BSODing and crashing really quickly when I tried reducing the QPI volts to 1.295. When set to 1.335v, it is fine and rock stable 24/7.
 
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The image you posted isn't proof that your memory is running with different timings - it is just a picture of the BIOS screen. You could set everything to whatever you want to, take a picture and say "oh look, all my timings are different". Post a picture of CPU-Z or similar to show what you are really running. My guess is even if your BIOS allowed you to save different timings it will override it and make them all run at the same speed (probably the lower speed of 8-7-7-20).
 
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Well, when I set all three channels to 7-7-7-20, only 8 Gb is usable like this:

8gb.png




Then when I set Channel A + B to 7-7-7-20, and channel C to 8-7-7-20, all 12 Gb becomes usable:

12gb.png


CPU-Z just says 7-7-7-20, 1T.

I knew that channel C was the one not working because its timings are empty when going into the bios after only 8 Gb is usable, and I'm also sure that that is where the pair with the completely different serial number to the other two is installed.

I tried in Sandra Lite and this is just confusing:

sandramemory.png


It says I have 4 modules at 8-7-7-20, and 2 at 9-7-7-20 :x
 
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I forgot that Gigabyte and MSI still have this "feature" in their BIOS'. Based on what I have seen and from feedback, it's mostly useless and frequently unstable. If you have a system that won't run all of your memory at the same timings, you have a problem somewhere.
 
Its a problem with setting the timings too tight. Mine isnt unstable though, no crashes or problems with 1.335v QPI.
 
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