G.Skill PC3-12800 RAM Issues

[MMIKEE]

I have (4) G.Skill F3-12800CLD9-8GBRL DDR3-1600 PC3-12800 4096MB Modules installed on my ASUS M4A89TD Pro/USB3 Motherboard with latest BIOS v2001. I purchased and installed a pair of these in Slots 1 & 3 / DIMM-A1 & B1 (Blue Slots) during 03/2011 and later purchased and installed a 2nd pair of these in Slots 2 & 4 / DIMM-A2 & B2 (Black or Dark Gray Slots) during 08/2011. Each pair is a matched set of 2 sticks.

My issue is that the latest versions of CPU-Z, AMD?s AOD etc all report that Slots 1 & 2 / DIMM-A1 & A2 are PC3-10700 = 667 MHz and Slots 3 & 4 / DIMM-B1 & B2 are PC3-12800 = 800 MHz.

NOTE: Slot 1 = DIMM-A1 (Blue) / Slot 2 = DIMM-A2 (Black) / Slot 3 = DIMM-B1 (Blue) / Slot 4 = DIMM-B2 (Black) The 1st pair of Memory Sticks is installed in the DIMM-A1 & B1 (Blue) slots, and the 2nd pair of Memory Sticks is installed in the DIMM-A2 & B2 (Black) slots.

I have experimented with various BIOS Memory Auto & Manual settings but regardless of anything I have done so far, this has yet to have any effect on these reported MHz frequencies. Currently, I am clocking ALL of this DRAM at 800MHz (1600 MHz) and am using the G.Skill recommended timings.

I have Image Snapshots of some CPU-Z screens to display relevant information regarding this Motherboard, CPU, Memory etc. but I am not allowed to post them yet.

I would appreciate an explanation of why this is occurring and whether or not it is an actual issue with the Motherboard, RAM or the BIOS setup.

I have not swapped any of these memory sticks to different Slot / DIMM locations because I don?t see how that will change what is being reported by CPU-Z and AMD?s AOD.

Note: This PC / Motherboard / CPU / RAM combo works AOK and I am not having any problems that I am aware of.

[RamJam]

Hmmm

What CPU are you running? Also what does CPU-Z show in the Memory Tab? Some AMD CPUs are restricted with RAM, i.e. some can only run 1600 (or 1333 and some at 1066) with 1 DIMM per channel.

[MMIKEE]

G.Skill PC3-12800 RAM Issues

I have all this info in my Image Snapshots which I can NOT post yet, so...
AMD Phenom II X6 1100T / DDR3 Dual Channel 16384 MBytes Unganged NB Freq=2408.0 MHz DRAM Freq=802.7 MHz FSBRAM=1:4 9-9-9-24-40-2T

[GSKILL TECH]

Looks spot on!

DDR is double data rate, whenever you see "MHz" it is real frequency, not DDR frequency, so 802.7 x 2 = DDR3-1605.4

This is one of the top combinations out there as far as perfect compatibility.

Thank you
GSKILL TECH

[MMIKEE]

G.Skill PC3-12800 RAM Issues

Thank you G.Skill Tech, however you didn't provide an explanation regarding:

My issue is that the latest versions of CPU-Z, AMD?s AOD etc all report that Slots 1 & 2 / DIMM-A1 & A2 are PC3-10700 = 667 MHz and Slots 3 & 4 / DIMM-B1 & B2 are PC3-12800 = 800 MHz.

NOTE: Slot 1 = DIMM-A1 (Blue) / Slot 2 = DIMM-A2 (Black) / Slot 3 = DIMM-B1 (Blue) / Slot 4 = DIMM-B2 (Black) The 1st pair of Memory Sticks is installed in the DIMM-A1 & B1 (Blue) slots, and the 2nd pair of Memory Sticks is installed in the DIMM-A2 & B2 (Black) slots.

Slot 1 = 1st RAM Pair, Slot 2 = 2nd RAM Pair, Slot 3 = 1st RAM Pair and Slot 4 = 2nd RAM Pair.

I would appreciate an explanation of why this is occurring and whether or not it is an actual issue with the Motherboard, RAM or the BIOS setup.

[GSKILL TECH]

Not an issue.

The "Max Bandwidth" is what the memory can default to. Earlier production kits were all 10700, but recently 12800 was accepted. Either way, it doesn't matter. The memory is you have is above standard, so you shouldn't be using AUTO settings anyway. So it really doesn't matter what it shows.

Thank you
GSKILL TECH

[MMIKEE]

Thank you G.Skill Tech,

I understand this much better now. I also did some more research on my system and am adding this information to help clarify this for other users who may use ASUS motherboards.

NOTE: I had incorrectly assumed that the CPU-Z and AMD's AOD ram slot assignments are the same as the Motherboard physical ram slot sequence from CPU outward... They are NOT... On this motherboard, they are:

CPU-Z: Slot 1 = DIMM-A1 (Blue) / Slot 2 = DIMM-B1 (Blue) / Slot 3 = DIMM-A2 (Black) / Slot 4 = DIMM-B2 (Black)

AOD: Slot 0 = DIMM-A1 (Blue) / Slot 1 = DIMM-B1 (Blue) / Slot 2 = DIMM-A2 (Black) / Slot 3 = DIMM-B2 (Black)



NOTE: the 2nd pair (08/2011) has ?XMP? on the RAM labels, but the 1st pair (03/2011) does not.


CPU-Z had previously reported that Slots 1 & 2 / DIMM-A1 & B1 are PC3-10700 = 667 MHz and Slots 3 & 4 / DIMM-A2 & B2 are PC3-12800 = 800 MHz.

I reversed the 1st and 2nd pair of RAM and discovered ?Max Bandwidth? is different and as reported above and below.

CPU-Z now reports that Slots 1 & 2 / DIMM-A1 & B1 are PC3-12800 = 800 MHz and Slots 3 & 4 / DIMM-A2 & B2 are PC3-10700 = 667 MHz.

Finally UNCONFUSED now...

[Tradesman]

Glad to hear it, Enjoy!