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MP 1,1-5,1 Samsung 1333 Pc3 10600R run 1066Mhz.
- Thread starter zozomester
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If I don't know wrong, you have to use 2Rx4 or lower rank dimms for 1333MHz. Higher "R(rank)" means for cMP; lower speed and lower compability. Also, I don't remember correctly but it should be 36 chip memory per cpu limited wrote on cMP's manual.
Mine rams also Samsung but 2Rx4. Work flawless.
Yes! I have the exact same modules and can confirm this: Quad Rank (4R) dimms only run @ 1066MHz...
...but it shouldn't worry you to much as they have the shorter CAS latency: They run @ CL7 instead of CL9 for 1333. And, as 7 cycles of 1066MHz are a shorter period of time than 9 cycles of 1333MHz, the ram's response time @ 1066 is even faster than @ 1333. In general you can say that, in cases of large data transfers to or from the ram, the higher clocked is faster. But when a lot of random small accesses happen, the opposite is the case.
I have 2R sticks as well and did a lot of extensive testing on that. With ten runs of Geekbench for each configuration, i had the slightly better memory-scores for the "slower" ram. But all within a range of +/- 5%. In a more "real life" scenario like Cinebench there wasn't any notice- or reproduceable difference at all! So this should be a more cosmetic thing, with very small advantages for one or the other side, depending on what you use your machine for.
Myself, i am happily using the "slow" quad-rank-dimms now.
...but it shouldn't worry you to much as they have the shorter CAS latency: They run @ CL7 instead of CL9 for 1333. And, as 7 cycles of 1066MHz are a shorter period of time than 9 cycles of 1333MHz, the ram's response time @ 1066 is even faster than @ 1333. In general you can say that, in cases of large data transfers to or from the ram, the higher clocked is faster. But when a lot of random small accesses happen, the opposite is the case.
I have 2R sticks as well and did a lot of extensive testing on that. With ten runs of Geekbench for each configuration, i had the slightly better memory-scores for the "slower" ram. But all within a range of +/- 5%. In a more "real life" scenario like Cinebench there wasn't any notice- or reproduceable difference at all! So this should be a more cosmetic thing, with very small advantages for one or the other side, depending on what you use your machine for.
Myself, i am happily using the "slow" quad-rank-dimms now.