Let's talk about Drive Strength

[GV2NIX]

I've been trying to read up on this topic for the past few weeks, but I'm still not exactly sure what to think of it. I haven't changed my drive strength settings at all, and I don't seem to be running into any problems. However, I would like to open a discussion so that more of us can learn more about what it does, what risks it may present, and under what circumstances it should be manipulated.

I know it applies mostly to those of us using TCCD. Some people have gotten better results by upping their drive strength and/or data drive strength. I would like to know more about it, and I think others would too. I want to leave the topic open to discuss all of the other mysterious RAM timings on DFI boards aside from the usual Tcl, Trcd, Tras, and Trp. DFI-Street is too extensive, I think we should have our own guide here! :)

So, that's that. Fire away! I'll keep posing as I learn more. Thanks guys!

[gvblake22]

I heard the Tref has some signifigant impact on overclockability with TCCD/TCC5 based RAM...
Other than that, I'm about as baffled on all DFI's RAM timings as you are
I printed off a total of like 30 pages of information just on RAM and BIOS settings from DFI-Street, but it's a lot to wade through...

I found THIS thread to be the most informational though.

DRAM Drive Strength

Settings = Auto, 1-8 in 1.0 increments.

Paraphrased From Adrian Wong’s site:http://www.rojakpot.com/ “Sometimes called driving strength. This feature allows you to control the memory data bus' signal strength. Increasing the drive strength of the memory bus can increase stability during overclocking. DRAM drive strength refers to the signal strength of the memory data line. A higher number means a stronger signal and is generally recommended for an overclocked module to improve stability. Supposedly TCCD works better with weak drive strength while just about everything else prefers a stronger signal.�

From bigtoe: “If you leave the option at Auto this will set a weak drive strength, this is good for TCCD based modules but bad for anything else. From testing and debugging the board I have concluded the following. Options 1 3 5 7 are all weak, as is Auto, setting. 1 is actually the weakest option with 7 being as close to the normal weak setting DFI will allow us. Options 2 4 6 8 are the Normal settings, with 8 being the highest strength setting. If you are using TCCD you may want to try 3 5 or 7 as the drive settings as they usually seem to allow the modules to clock well. If you are using VX, or the new BH Gold, or any other modules from the OCZ range you may want to try 8 or 6.�

Large Influence on Stability.

Suggested Settings for DFI: From bigtoe: “If you are using TCCD you may want to try 3 5 or 7 as the drive settings as they usually seem to allow the modules to clock well. If you are using VX, or the new BH Gold, or any other modules from the OCZ range you may want to try 8 or 6.�


DRAM Data Drive Strength

Settings = Levels 1-4 in 1.0 increments.

From Adrian Wong’s site: http://www.rojakpot.com/
"The MD Driving Strength determines the signal strength of the memory data line. The higher the value, the stronger the signal. It is mainly used to boost the DRAM driving capability with heavier DRAM loads (multiple and/or double-sided DIMMs). So, if you are using a heavy DRAM load, you should set this function to Hi or High. Due to the nature of this BIOS option, it's possible to use it as an aid in overclocking the memory bus. Your SDRAM DIMM may not overclock as well as you wanted it to. But by raising the signal strength of the memory data line, it is possible to improve its stability at overclocked speeds. But this is not a surefire way of overclocking the memory bus. In addition, increasing the memory bus signal strength will not improve the performance of the SDRAM DIMMs. So, it's advisable to leave the MD Driving Strength at Lo/Low unless you have a high DRAM load or if you are trying to stabilize an overclocked DIMM."

Large Influence on Stability.

Suggested Settings for DFI: Many have suggested using Level 1 or 3, if you have CPC enabled. With CPC, anything above level 1 gives some users extreme instability. Some users like level 3 with CPC enabled. Some others have had success with using level 2-4 if CPC is disabled. I had good luck with CPC enabled and Level 4. (Higher = Faster)

[GV2NIX]

Hey blake, sorry for not posting sooner, but I've been going nuts here being it's my final week!

Anyways, that's a great resource! It sheds some light on the topic. I was curious, when he talks about "heavy DRAM load" he seems to be saying that multi/double-sided DIMMs are considered "heavy DRAM loads"

So, it's advisable to leave the MD Driving Strength at Lo/Low unless you have a high DRAM load or if you are trying to stabilize an overclocked DIMM.

So, by this logic, anyone with double-sided DIMMs should benefit from a higher data drive strength?

[gvblake22]

Originally Posted by GV2NIX

So, by this logic, anyone with double-sided DIMMs should benefit from a higher data drive strength?

From the description, it does seem that way :?

[GV2NIX]

Well, I guess that takes care of drive strength and data drive strength. I can't imagine finding anything more informative than the stuff you posted, thanks! :)

Ok next. We all pretty much know how the blue items work. Although I'm sure we won't get through all of them, I would like to hear thoughts. Hopefully we can shed some light on these mysteries!


Ram Multi
CPC
Tcl
Trcd
Tras
Trp


Trc
Trfc
Trrd
Twr
Twtr
Trwt
Tref
Twcl
Bank Interleve
Dynamic Skew Control
Skew Value
Max Async
Read Preamble
Idle Cycle
Dynamic Counter
R/W Que Bypass
Bypass MAX
32 Bit Gran