Memory latency

[happolk]

My new Corsair TWIN2X1024-5400C4PRO is SPD programmed at 4-4-4-12. Sanda reports it is running 4-5-5-15, slower than the stock Samsung DDR-2 PC4300 reported as running at 4-4-4-11. The Gateway BIOS for the Intel D945GBI board does not report or allow adjustment of memory parameters. It appears that the 200FSBx4=800 is running at 4:3 or 533. Intel says the board is capable of 667 (5400), but without BOIS adjustment, it appears fixed at 533 (4300). Am I getting 533 with 4-5-5-15 latencies? If I returned the 5400C4PRO (15% restocking fee) for say Corsair TWIN2X1024-4300C3 would I get 533 with 3-3-3-8 latencies? Voltage appears fixed at 1.8V. Would the Corsair 4300C3 tested at 1.8V or the GeIL DDR2 533's rated at 1.8 to 2.4V be stable at their stated 3-3-3-8 latencies if fixed at:o: 1.8V? Any test program that reports acutal memory parameters when BIOS won't tell you?

Thank you.

[CMC_SAVAGE]

There is no guarantee for latencies and timing when you are mixing different

brands of memory.

Since you have no BIOS settings available, it really does'nt matter what you have, the MOBO will adjust everything for optimal performance.

[Wired]

There's no way to override the auto BIOS settings. CPU-Z will tell you the actual memory timings under the MEMORY tab.

[RJLeong65]

There's no way to override the auto BIOS settings. CPU-Z will tell you the actual memory timings under the MEMORY tab.

 

Actually, most OEM motherboards (which are, motherboards that are specific to big-name OEM systems) run on fixed, JEDEC-approved (or JEDEC-standard) CAS and RAS timings for any given memory clockspeed. What that means is that DDR2-533 memory will always run at CAS 4-4-4-11 timings on that Gateway system no matter which DDR2-533 memory modules that you use. And DDR2-667 modules will always run at CAS 4-5-5-15 timings.

 

Same thing with my brother's Dell Dimension 8300 system: Though it uses the i875P chipset, PAT cannot be enabled at all whatsoever with that motherboard, and all memory will run at a fixed set of CAS 3-3-3-8 timings @ DDR400 regardless of which memory modules he used. What's more, if anything, the i875P-based systems with PAT disabled will actually have a lower memory bandwidth, and therefore slower performance, than any i865PE-based system.

 

In all of the above instances, the SPD is used only to set the memory clockspeed.

 

Those factors, combined with the relatively low, JEDEC-standard voltage output of the memory slots, leave the OEM system owner with the System Select modules as the best choice for OEM systems (and BYOPC systems which lack user-adjustable DDR voltage), since most widely available, store-bought DDR and DDR2 memory requires a higher voltage than the JEDEC standard for optimal stability.

[Wired]

I know :) I was talking about CPU-Z just to make sure he'll look @ the right tab, especially if he uses it for non-OEM systems.