G.Skill PC4800 512Mb LA

This memory has Samsung TCCD 440 chips. These chips are newer then the 431 on the LE and like higher voltages, on my DFI nF3 UT 250Gb they ran fine with 3.1v VDDR.



The memory is rated at DDR600 3-4-4-8 (SPD). I tested these modules at 2.5-3-3-6 1T!

2x 256MB DDR600 2.5-3-3-6 1T Dual Channel (10 pass Memtest86+)

BIOS Settings

Vddr: 2.7v
Tcl: 2.5
Trcd: 3
Tras: 6
Trp: 3
Trc: 9
Trfc: 14
Trrd: 2
Twr: 2
Twrt: 2
Trwt: 2
Tref: 4708 (166MHz 1.95us)
Twcl: 1

Bank int.: Enable
Skew control: 255 +
Drive strength: 7
Data strength: 2
Max. Async: 8ns
Read Preamble: 5ns
Idle Cycle: AUTO
Dyn. Counter: Enable
R/W Bypass: 16x
Bypass Max: 7x
32Bit Gran.: Disable

The settings above are set for high performance and stability. The Tref can be tuned higher to e.g. 3.9us or 15.6us for better performance. Tref=3072 is 200MHz 3.9us refresh interval. You can also set Trfc to 12.

If those settings listed above are not stable, you can change the following to make your memory stable and maintain good performance:

- Lower the refresh interval (Tref)
- Trrd to 3
- Twr to 3
- Trwt to 3
- Idle Cycle at 128 or 256

Remember, always try CL2.5-3-3-6 1T first to get the maximum performance out of your TCCD. I recommend change these settings when you cannot get yours stable in any way.

Test known-how’s

- Data strength 2 is the best value for stability, I recommend not increasing or decreasing it. But always test which setting is best for you.

- Always set the bank interleave to enable when you are using two modules. This will increase the performance and stability

- Set Drive Strength to 7. Higher and lower only gives me instability. When I set 1 ~ 3, the system wouldn’t even boot!

2x 256MB DDR640 2.5-4-3-6 1T Dual Channel (10 pass Memtest86+)

Unfortunately I cannot do 10 pass stable with Memtest86+ at 320MHz CL2.5-3-3-6 1T. I only get 5 pass stable. The problem is my memory, one module being not quite as good as the other.

BIOS Settings

Vddr: 2.9v
Tcl: 2.5
Trcd: 4
Tras: 6
Trp: 3
Trc: 9
Trfc: 16
Trrd: 3
Twr: 3
Twrt: 3
Trwt: 2
Tref: 4708 (166MHz 1.95us)
Twcl: 1

Bank int.: Enable
Skew control: 128+
Drive strength: 7
Data strength: 1
Max. Async: 9ns
Read Preamble: 5ns
Idle Cycle: AUTO
Dyn. Counter: Enable
R/W Bypass: 16x
Bypass Max: 7x
32Bit Gran.: Disable

The settings above are set for high stability. These settings are stable for better modules. So you have to test it by yourself. If these settings are stable with your ram, you can lower the Max. Async. to 8ns for even better performance. You also can lower the Trrd and Twr to 2.

For better stability you can set the Idle Cycle time to 128 or 256.

Increasing the Trfc by 1 also will increase some stability to your memory.

Test known-how’s

- When you use 2x256MB TCCD modules, I recommend you not to use to much signal strength.



I hope this guide will help you on your road to DDR600 speeds with your brand new S939 setup!

Question/Comments: forum thread


This guide has been written by kakaroto.