ram timing info
(by jess)
DRAM Timings:
**Dram Frequency Set (Mhz)**= 100(Mhz)(1/02), 120(Mhz)(3/05), 133(Mhz)(2/03), 140(Mhz)(7/10), 150(Mhz)(3/04), 166(Mhz)(5/06), 180(Mhz)(9/10), 200(Mhz)(1/01).- This is simply the Dram ratio option.
This option sets the Dram ratio. With a64, the ratios are not always written in stone, for example 166(5/06) isn’t always 5/6 ratio. You can refer to this chart for the exact ratios (they may not all be right, and thanks to Oskar_WU for his help with the chart) Large Influence on Bandwidth/Stability.
**Command Per Clock (CPC)**= Auto, Enable(1T), Disable(2T), this is also called Command rate. It is best, in most cases to Disable for (2T) w/ 2x512 Ram modules.
Large Influence on Bandwidth/Stability.
PLEASE NOTE THAT IF YOU ARE USING A "CO" REV. CPU THIS OPTION (CPC) WILL NOT APPEAR IN BIOS. THIS IS BECAUSE "CO" REV. CPU'S DO NOT SUPPORT 2T TIMING, ONLY 1T. IF YOU HAVE A "CG" REV. CPU, YOU WILL BE ABLE TO SELECT EITHER AUTO, 1T, OR 2T.
*Cas Latency Control (tCL)**= 1, 1.5, 2, 2.5 3, 3.5, 4, 4.5. I would suggest only using, 2, 2.5, and 3.
Added Note: This is the first timing that most ram companies rate their ram with. For example, you might see ram rated at 3-4-4-8 @275mhz. this is the 3, in than situation.
2 yields the best performance, but, unless you have either Winbond BH-5, or BH-6, it is unlikely you will be able to reach you maximum over clock at CAS2. CAS3 is usually yields the best stability/over clock.
PLEASE NOTE; IF YOU HAVE WB-BH-5/6, YOU MOST LIKELY WILL NOT BE ABLE TO USE CAS3, AND SOME MAY NOT BE ABLE TO USE CAS2.5, MY BH-6 WILL NOT POST AT CAS2.5, OR CAS3, IT WILL ONLY POST AT CAS2.
Slight Influence on Bandwidth / Large Influence on Stability.
**RAS# to CAS# delay (tRCD)**= 0, 1, 2, 3, 4, 5, 6, 7. I would suggest only using 2-5. Added Note: This is the second timing that most ram companies rate there ram with. For example, you might see ram rated at 3-4-4-8@275mhz. this is the 4, in than situation.
2 yields the best performance, and 4-5 (5 is usually overkill) yields the best over clock. Most rams will not be able to use 2, and reach their max OC.
Large Influence on Bandwidth/ Stability.
*Min RAS# active timing (tRAS)*= 00, 01, 02, 03, 04, 05, 06, 07, 08, 09, 10, 11, 12, 13, 14, 15. I would suggest only 00, and 5-10.
Added Note: This is the fourth timing that most ram companies rate there ram with. For example, you might see ram rated at 3-4-4-8 @275mhz. this is the 8, in that situation.
This is a much debated timing. Some may argue that 00, 05, or 10 is the faster/most stable. But I really think there isn’t a right answer for this one, it all depends on your ram. But, if you need a good starting point, usually most/all ram can achieve their max OC on 10 tRAS, even if one of the other settings is faster.
Slight Influence on Bandwidth/Stability.
**Row Precharge timing (tRP)**= 0,1, 2, 3, 4, 5, 6, 7. I would suggest using only 2-5.
Added Note: This is the third timing that most ram companies rate there ram with. For example, you might see ram rated at 3-4-4-8 @275mhz. this is the 4, in that situation.
2 yields the best performance, and 4-5(5 is usually overkill) yields the best over clock. Most ram will not be able to use 2, and reach there max OC.
Large Influence on Bandwidth/Stability.
EGIN BLUE HERE
**Row Cycle Time(tRC)**= 7-22 in 1.0 increments. 7 yields the best performance, 15-17(i think 17 is overkill) yields the best stability/over clock. I would start at 15, and work your way down from there. Also, 7 is usually much too tight, for most ram.
Large Influence on Bandwidth/Stability.
**Row Refresh cycle time (tRFC)**= 9-24 in 1.0 increments. This timing is usually always set to 2-4 clocks higher that the tRC.
10 yields the best performance (well 9 would, but 9 is too tight), and 17-19(I think 19 is overkill) yields the best stability/over clock. I would start at 17 and work your way down.
Large Influence on Bandwidth/Stability.
*Row to Row Delay(also called Ras to Ras delay)(tRRD)*= 0-7 in 1.0 increments. 00 yields the best performance and 4 (I think anything above that is overkill) yields the best stability/over clock. I know that 00 sounds odd, but it works great for me, even at 260 MHz
Slight Influence on Bandwidth/Stability.
*Write Recovery Time (tWR)*= 2, 3. 2 yields better performance, and 3 yields better stability/over clock.
Slight Influence on Bandwidth/Stability.
*Write to read Delay (tWTR)*= 1, 2. 1 yields better performance and 2 yields better stability/over clock.
Slight Influence on Bandwidth/ Stability.
*Read to Write delay (tRTW)*= 1-8 in 1.0 increments. 1 yields better performance, and 4(I think any above 4 is overkill) yields better stability/over clock.
Slight Influence on Bandwidth/Stability.
Refresh Period (tREF)*= 0032-4708 in variable increments.
1552= 100mhz(?.?us)
2064= 133mhz(?.?us)
2592= 166mhz(?.?us)
3120= 200mhz(?.?us)(my sweat spot w/ Bh-6 at 250+mhz , your mileage may vary)
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3632= 100mhz(?.?us)
4128= 133mhz(?.?us)
4672= 166mhz(?.?us)
0064= 200mhz(?.?us)
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0776= 100mhz(?.?us)
1032= 133mhz(?.?us)
1296= 166mhz(?.?us)
1560= 200mhz(?.?us)
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1816= 100mhz(?.?us)
2064= 133mhz(?.?us)
2336= 166mhz(?.?us)
0032= 200mhz(?.?us)
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0388= 100mhz(15.6us)
0516= 133mhz(15.6us)
0648= 166mhz(15.6us)
0780= 200mhz(15.6us)
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0908= 100mhz(7.8us)
1032= 133mhz(7.8us)
1168= 166mhz(7.8us)
0016= 200mhz(7.8us)
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1536= 100mhz(3.9us)
2048= 133mhz(3.9us)
2560= 166mhz(3.9us)
3072= 200mhz(3.9us)
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3684= 100mhz(1.95us)
4196= 133mhz(1.95us)
4708= 166mhz(1.95us)
0128= 200mhz(1.95us)
I suppose that the tREF, like the tRAS, is not an exact science. it seems that the 15.6us, and 3.9us settings seem to work good, and that the 1.95us settings give usual results (extremely low bandwidth for me)
The unknown (?.?us) are kind of shot in the dark, for me, out of all the setting 3120 gave the best balance of performance, and stability, but I feel this will greatly vary from one ram to another
Slight Influence on Stability.
Write CAS# Latency (tWCL)**= 1-8, I can only post using auto or 1. If you have had any successes with this timing please post here.
Added Note by RGone… #5 in setting works on my board with “any” brand or size and speed of memory!
Large Influence on Stability.
*DQS skew Control*= Auto, Increase Skew, Decrease Skew. Increase for performance, and Decrease for Stability.
Slight Influence on Bandwidth/Stability.
*DQS Skew Value*= 0-255 in 1.0 increments. This is the value that is Increased or Decrease when you set the DQS skew control. This is not a very sensitive timing I would try 50-255.
Slight Influence on Bandwidth/Stability.
DRAM Drive Strength**= Level 1-4 I would only suggest using Level 1 or 3, if you have CPC enabled. With CPC, anything above level 1 gave me extreme instability, some reported that level 3 work good with CPC enabled, although this didn’t work for me. Some others have had success w/ using level 2-4 if CPC is disabled.
Large Influence on Stability.
*Max Async. Lantency*= 00.0-15.0 in 1.0 increments. I would suggest trying 5.0-10.0
Slight Influence on Bandwidth/Stability.
* Read Preamble time*= 02.0-09.5 nano sec, in 0.5 increments. I would suggest 4.0-7.0 depending on ram.
Slight Influence on Bandwidth/Stability.
*Idle Cycle Limit*= . 000-256 in varied increments. I would try 16-32 clocks.
Slight Influence on Bandwidth/Stability.
*Dynamic Counter*= Auto, Enable, Disable. Enable for very slight performance increase. Disable for slight stability increase.
Slight Influence on Bandwidth/Stability.
*R/W Queue Bypass*= 2x, 4x, 8x, 16x. I would suggest using 8x or 16x. 2x or 4x for max OC.
Slight Influence on Bandwidth/Stability.
*Bypass Max*= 0x-7x in 1.0 increments. I would suggest 5x-7x for max performance. 0x-4x for max OC.
Slight Influence on Bandwidth/Stability.
*32 byte Granulation= Auto, Disable (8burst), enable (4burst). Try Disable (8burst) for more bandwidth. Try enabling 4 burst for more stability
Slight Influence on Bandwidth.
Genie bios Settings
Dram Configuration=(see above post)
_____________
FSB Bus Frequency= 200-456mhz in 1mhz increments, this is what is commonly called HTT(most know it as FSB)
Agp Bus Fequency= 66-100mhz in 1mhz increments. it is not neccasary to set to 67mhz to get a pci lock, like on other NF3 mobo's, but it wont hurt to do it, just for safety
LDT Downstream width= Auto(16bit), 8bit. i would suggest leaving on auto for best perfomance
LDt Upstream Width= Auto(16bit), 8bit. i would suggest leaving on auto for best performance
LDT/FSB Frequency Ratio= 1x, 1.5x, 2x, 2.5x, 3x, 4x, 5x. i would only suggest using 5x for use in combo w/ 200mhz HTT. Try 4x up to 235-245. 3x up to 245-265. and 2.5x from there on up. if your going for max HTT(like something over 300-350) try 2, 1.5 and 1x.
CPU/FSB Frequency Ratio= 4x-20x in 0.5 increments. THis is your CPU multipier(multipy this times your FSB Bus frequency to get you cpu frequency. i would suggest NOT using 4x, or 0.5 multis, because this puts your ram on a ratio. you may only us your stock multi, and lower.
K8 Cool 'n' Quiet Support= Auto(enable), disable. Mobo automaticly scales down VID/FID at system idle. DISABLE for overclocking!!
CPU VID Control= 0.800v-1.550v in 0.025v increments. VID means Voltage IDentification. This is simple the Vcore.
CPU VID Special Control= 104%, 110%, 113%, 123%, 126%, 133%, 136% above VID. you multipy this by CPU VID control to get your total Vcore. (113%=1.13, 104%=1.04)(so if Vcore is 1.55, and specail is 110% you would have 1.55v x 1.1=1.705v)