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Why the need for such a guide? On several web logs there are a lot of people who upgraded their S754 platform to the new S939 with PCI Express. This is because the FX processor is not the only CPU anymore with the S939 socket. Most of these people want high HTT speeds to overclock their processor and memory so they buy Samsung TCCD or low latency memory like Winbond BH5/UTT.
Recently G.Skill PC4400/4800 became the hottest memory on the market together with OCZ PC4800 based on Samsung TCCD. This memory requires a high HTT speed, so the system must be overclocked.
A big problem that occurs when trying to reach high HTT speed is the memory that doesn’t want to run that speed although it is rated at speeds 275 or 300MHz. This results in many errors showing up in Memtest86+ and sudden BSOD in Windows. Some people might think this is caused by faulty memory, but nothing could be more untrue.
There is another culprit here, the processor on-die memory controller. The overclocking potential of every memory controller is different, there is no doubt that there are bad and good ones. In the low- and midrange processors from AMD the quality of the controller is not always consistent, this is a problem for most of the users. This is not so much an issue if you plan to buy a high end FX processor.
The low- and mid range cores at this moment are:
- Newcastle
- Winchester/Venice
High end cores are:
- Clawhammer 1MB
- San-diego 1MB
Soon AMD will launch two new cores named “Venice and San Diego” (revision E3 and E4). These cores have an upgraded instruction set (SSE3) and a better memory controller which is capable of addressing four memory modules in Dual Channel.
Unfortunately the only way to find out if your CPU's memory controller is by testing it, the core revision or stepping does not tell you enough. All I can is recommend is; buy the most recent processor. This will increase the chance that you have a new memory controller.
The chance that you will have a “bad” memory controller on the Winchester core is 6 of 10. When you have a good controller, this does not mean you will reach those speeds 100% around DDR500~600. The RAM must be tuned, that’s why I've created this guide.
In this guide I will help you to get your TCCD memory running stable at your stock rating and above.
I have used the following modules for testing:
- G.Skill PC4400 1GB LE (Samsung TCCD 431) (2x512MB)
http://www.xs4all.nl/~famchow/DFI NF4 guide/GSKILL 1GBLE.jpg
- G.Skill PC4800 512 LA (Samsung TCCD 440) (2x256MB)
http://www.xs4all.nl/~famchow/DFI NF4 guide/GSKILL 512LA.jpg
If you use other TCCD based memory products like OCZ, PQI, Kingston, Corsair etc. you also can use this guide, but some results may vary from what i saw with this gskill memory.
The Goals:
best timings=performence for 2x 512MB at
275MHz (DDR550) (CL2.5-3-3-6 1T)
300MHz (DDR600) (CL2.5-3-3-6 1T)
320MHz (DDR640) (CL2.5-4-3-6 1T)
Clear I think
Users with a DFI nF4 Ultra/SLI motherboard would have known that this board has a very detailed memory setting menu in the BIOS. These settings are same on the DFI nF3 UT 250Gb board. If you don’t know what all those settings mean, I recommend you to read this guide first
All those settings are important to tune the memory to be able to run at DDR600 and beyond. For users who do not own a DFI nF4, they can use A64tweaker 0.5 for windows, this program allows you to change advanced memory timing related settings straight from within Windows.
The Method
To test stability, I will use a well-known program called Memtest86+. This program is implemented in the BIOS on the DFI nF4. You can download the new bios from the DFI website.
1. Test which module combination works best on your motherboard. This is a strange step. Sometimes two modules works better if you switched them from place. Always use the orange banks. (2 and 4)
2. Test the memory on e.g. DDR600 with minimum voltage. (~2.7v). If you get 20 to 50 errors in Memtest86+ you can tune the memory from there. If you get plenty of errors you have to increase the voltage or lower the clock speeds.
3. If you are done with tuning on a specific speed, try to clock further with more VDDR or signal strength (Drive/Data strength).
In this article you have seen me writing about stable speeds. My criteria of stable are a minimum pass of 10 times in Memtest86+ test 5 without errors. Piece of cake you might think, but this won’t be easy especially when you are trying to get high speeds stable with 1GB ram. This kind of stability is game stable and Prime stable for at least an hour.
Bios Version
As you might know, DFI is a motherboard manufacturer that often releases new BIOS updates which is very great. I use the bios 3.10P (P for Performance) which gives you better compatibility for different kind of memory. I recommend using Oskar Wu beta bioses for the best support and performance for TCCD or BH5/UTT.
Which TCCD is the best?
A difficult question to answer is; what revision if TCCD is the best? At this moment there are five revisions: 425, 431, 437, 440, 449, 504 and 507. According to some users experience, newer TCCD are performing better at a higher voltage
Test Setup
I used a competitively priced A64 Winchester CPU in test setup, rather then an overly expensive A64 FX-?? one.
- Athlon 64 3000+ (CBBHD 0448 RPMW)
- DFI nF4 Ultra-D rev. A02
- G.skill PC4400 & 4800 LE/LA
- Tagan 480Watt-U22
I had quite a bit of luck with the on-die memory controller of the A64 3000+ as it turned it runs at DDR600 speeds flawlessly.
Cooling: I can’t stress this enough; use an 80mm fan or bigger to cool down your memory as it has a very large impact on the result. At lower speeds and voltage the TCCD chips hardly get hot, but when pushing the envelope they start cooking and this will deter the overclocking potential.
2x 512MB DDR550 2.5-3-3-6 1T Dual Channel
http://www.xs4all.nl/~famchow/DFI NF4 guide/275MHZ_DC_GSKILL_1GBLE.jpg
http://www.xs4all.nl/~famchow/DFI NF4 guide/275MHZ_DC_GSKILL_1GBLE_sandra.JPG
BIOS Settings
Vddr: 2.7v
Tcl: 2.5
Trcd: 3
Tras: 6
Trp: 3
Trc: 9
Trfc: 12
Trrd: 2
Twr: 2
Twrt: 2
Trwt: 2
Tref: 3072 (200MHz 3.9us)
Twcl: 1
Bank int.: Enable
Skew control: 255 +
Drive strength: 7
Data strength: 4
Max. Async: 7ns
Read Preamble: 5ns
Idle Cycle: AUTO
Dyn. Counter: Enable
R/W Bypass: 16x
Bypass Max: 7x
32Bit Gran.: Disable
With these settings I got high performance and stability. The Tref (Refresh interval) can set to 4078 (166MHz 1.95us) for better performance.
If the settings mentioned above prove not to be stable, you can change the following:
- Max. Async. to 8ns
- Lower the refresh interval (Tref)
- Trrd to 3
- Idle Cycle at 128/256
These settings will increase stability and keep the performance at a descent level. If those settings are still unstable, there is something wrong with your memory or memory controller. You make sure your memory is not the issue; test the memory modules separately in bank 1 or 2.
When the memory works fine, then the problem must be the memory controller. You should disable the Command per Clock (CPC). If the problem is still there, you should consider lowering the speeds or, as a last resort, buy another processor.
2x 512MB DDR600 2.5-3-3-6 1T Dual Channel
http://www.xs4all.nl/~famchow/DFI NF4 guide/300MHZ_DC_GSKILL_1GBLE.jpg
http://www.xs4all.nl/~famchow/DFI NF4 guide/300MHZ_DC_GSKILL_1GBLE_sandra.JPG
BIOS Settings
Vddr: 2.7v
Tcl: 2.5
Trcd: 3
Tras: 6
Trp: 3
Trc: 9 (12)
Trfc: 14
Trrd: 2
Twr: 2
Twrt: 2
Trwt: 2
Tref: 3072 (200MHz 3.9us)
Twcl: 1
Bank int.: Enable
Skew control: 255 +
Drive strength: 7
Data strength: 2 (4)
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. 1.95us for better performance. Tref=3072 is 200MHz 3.9us refresh interval. You can also set Trfc to 12.
When those settings are not stable, you can change the following:
- Max. Async. to 8ns
- Lower the refresh interval (Tref)
- Trrd to 3
- Twr to 3
- Trwt to 3
- Idle Cycle at 128/256
If those settings are still unstable, be careful working with a higher voltage. TCCD does not like high voltage compare to Winbond BH5. Maybe the newer revision TCCD like higher voltage but this one doesn’t. Always start with a lower voltage and increase the voltage step by step to a satisfied value. As you see I only used 2.7v. higher voltage 2.8 ~ 2.9v only gives me errors in Memtest86+!
Always try to run at CL2.5-3-3-6 1T to keep the performance at a high level. But if there is no other way to get this stable you can raise the Trcd to 4. This will decrease the bandwidth by 100-150Mb.
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.
- Drive strength 7 is the best value for stability, I recommend not increasing or decreasing it.
- Always set the bank interleave to enable when you are using two modules. This will increase the performance and stability.
2x 256MB DDR640 2.5-4-3-6 1T Dual Channel
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.
http://www.xs4all.nl/~famchow/DFI NF4 guide/320MHZ_DC_GSKILL_512LA.JPG
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: 3072 (200MHz 3.9us)
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.
Tref is set 3072 for stable refreshrates. For benching I recommend a faster refresh rated 1.95us.
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!
Kakaroto,
Thnx [M] for improving the translation work!
Very Handy Articles related to Tweaking TCCD
- What is DQS? Discuss it! (
http://www.xtremesystems.org/forums/showthread.php?t=57925&highlight=DQS) ~by OPB!
updates
1 april 2005 - added new TCCD series.
12 april - small change Tref setting.
