Memory not running at proper speed

[xaephod]

Hey there. I am stumped at this issue. I have an XFX NFORCE 680i LT SLI mobo with a Q6600 in it. Not overclocked.

I have 2 sticks of 6400 ddr2 ram in there. Its OCZ Vista upgrade ram (pc2 6400 5-5-6), each is 2gigs, for a total of 4gigs of ram.
For some reason one of the sticks is running slow. The bios has not been messed with, never change the voltage. I even have a spare stick of the exact same ram, I swapped it out and its still running slow.

Here is the Sandra scan readout.

Logical/Chipset Memory Banks
Bank 0 : 2GB DIMM SDRAM
Bank 1 : 2GB DIMM SDRAM
Maximum Installable Memory : 2GB
Supported Memory Types : ECC DIMM SDRAM DDR2
Memory Bus Speed : 1x 667MHz (667MHz)
Maximum Memory Speed : 1x 667MHz (667MHz)
Width : 128-bit
Power Save Mode : No
Fixed Hole Present : No
Maximum Memory Bus Bandwidth : 10.42GB/s


Here you can see the first module is running at DDR2-666. I cannot figure this out. Is the mobo just crap and is dying?

Memory Module
Manufacturer : OCZ
Model : OCZ2VU8002G
Type : 2GB DIMM DDR2
Technology : 16x(128Mx8)
Speed : PC2-5300U DDR2-666
Standard Timings : 5-5-5-15 3-20-5-3
Version : 1.02
Memory DC Line : 1.80V
Timing @ 333MHz : 5-5-5-15 3-20-5-3
Timing @ 267MHz : 4-4-4-12 2-16-4-2
Timing @ 200MHz : 3-3-3-9 2-12-3-2

Memory Module
Manufacturer : OCZ
Model : OCZ2VU8002G
Type : 2GB DIMM DDR2
Technology : 16x(128Mx8)
Speed : PC2-6400U DDR2-800
Standard Timings : 5-6-6-18 3-24-6-3
Version : 1.00
Memory DC Line : 1.80V
Timing @ 400MHz : 5-6-6-18 3-24-6-3
Timing @ 333MHz : 4-5-5-15 3-20-5-3
Timing @ 267MHz : 3-4-4-12 2-16-4-2


I was going to get new ram till i tried my spare module. Now, I have no idea. new mobo? Thanks for any info.

 

[xaephod]

Anyone? If this has been dealt with before, please let me know.

 

[jaquith]

The RAM will not run at rated speed without you setting the speed in the BIOS.

Specs {hard to read} http://xfxforce.com/en-us/products/motherboards/6series/680.aspx#1
Memory speeds reaching 1200 MHz with SLI-Ready memory with EEP*
Memory Speed (MHz) 800 MHz

RAM OC Z OCZ2VU8002G http://www.ocztechnology.com/products/memory/ocz_ddr2_pc2_6400_vista_upgrade_2gb_module_4gb_kit

800MHz DDR2 CL 5-6-6-18 (CAS-TRCD-TRP-TRAS) @ 1.8V

I assume that you set the DRAM Frequency = DDR2-800MHz in the BIOS {a/k/a Memory Bus Speed}. In addition, since you have a Dual Channel MOBO I too assume that you purchased the RAM in a Matched Set of 2X2GB; otherwise you may have other problems. To run the RAM at rated speed you might need to set the DRAM Voltage = 1.8v~1.85v, and set the CAS timings as I've listed above {5-6-6-18}.

 

[xaephod]

I checked and the voltage is right on. Also the CAS timing is exactly as is specified. The memory is a matched set. I just checked again, in the bios it shows 800mhz at 5-6-6-18. When I check in Sandra, this is what I see:

Memory Module
Manufacturer : OCZ
Model : OCZ2VU8002G
Type : 2GB DIMM DDR2
Technology : 16x(128Mx8)
Speed : PC2-5300U DDR2-666
Standard Timings : 5-5-5-15 3-20-5-3
Version : 1.02
Memory DC Line : 1.80V
Timing @ 333MHz : 5-5-5-15 3-20-5-3
Timing @ 267MHz : 4-4-4-12 2-16-4-2
Timing @ 200MHz : 3-3-3-9 2-12-3-2

Memory Module
Manufacturer : OCZ
Model : OCZ2VU8002G
Type : 2GB DIMM DDR2
Technology : 16x(128Mx8)
Speed : PC2-5300U DDR2-666
Standard Timings : 5-5-5-15 3-20-5-3
Version : 1.02
Memory DC Line : 1.80V
Timing @ 333MHz : 5-5-5-15 3-20-5-3
Timing @ 267MHz : 4-4-4-12 2-16-4-2
Timing @ 200MHz : 3-3-3-9 2-12-3-2


that is wrong! I don't get it. Do you think its the ram or the Mobo? Cause I am out of ideas.

Thanks again!

 

[jaquith]

I don't use that App, the 'other' speeds are JEDEC standardize speeds. Chances are everything is fine, but to know 100% use CPUz - http://www.cpuid.com/softwares/cpu-z.html then look at the Memory -tab, it should show "Memory Frequency 400 MHz". DDR - Double Data Rate 400 MHz X 2 = 800 MHz.

 

[festerovic]

You bought both sticks together as a matched pair right?

 

[xaephod]

Yes. they came in the same package.
Here is the txt file from CPU-Z: Looks like its running slow, right?

Memory SPD
-------------------------------------------------------------------------

DIMM # 1
SMBus address 0x50
Memory type DDR2
Module format Regular UDIMM
Manufacturer (ID) OCZ (7F7F7F7FB0000000)
Size 2048 MBytes
Max bandwidth PC2-5300 (333 MHz)
Part number OCZ2VU8002G
Number of banks 2
Data width 64 bits
Correction None
Nominal Voltage 1.80 Volts
EPP no
XMP no
JEDEC timings table CL-tRCD-tRP-tRAS-tRC @ frequency
JEDEC #1 3.0-3-3-9-12 @ 200 MHz
JEDEC #2 4.0-4-4-12-16 @ 266 MHz
JEDEC #3 5.0-5-5-15-20 @ 333 MHz

DIMM # 2
SMBus address 0x51
Memory type DDR2
Module format Regular UDIMM
Manufacturer (ID) OCZ (7F7F7F7FB0000000)
Size 2048 MBytes
Max bandwidth PC2-5300 (333 MHz)
Part number OCZ2VU8002G
Number of banks 2
Data width 64 bits
Correction None
Nominal Voltage 1.80 Volts
EPP no
XMP no
JEDEC timings table CL-tRCD-tRP-tRAS-tRC @ frequency
JEDEC #1 3.0-3-3-9-12 @ 200 MHz
JEDEC #2 4.0-4-4-12-16 @ 266 MHz
JEDEC #3 5.0-5-5-15-20 @ 333 MHz

 

[xaephod]

 

[jaquith]

OCZ is "Rating" them above JEDEC, which isn't uncommon. But did "Memory -tab, it should show "Memory Frequency 400 MHz"" -- does it show 400 MHz??

If you look carefully at the CPUz example it shows this RAM as 1066 MHz JEDEC {8500/8 ~ 1066} but Corsair Rates the Kit as 1600 MHz.

 

[xaephod]

Yes, it say DRAM Frequency: 400.0 Mhz
5-6-6-18

 

[jaquith]

As I mentioned -> DDR - Double Data Rate 400 MHz X 2 = 800 MHz.

You are running at Rated Speed! You're good!

 

[festerovic]

It sounds like everything is reporting correct other than Sandra. Your RAM numbers look good, other than you need to manually set the timings in BIOS to get the fastest speeds out of them. Try 5-5-5-15 they may go as low as 4-4-4-12