Advanced AM2+ AMD Chipset Configuration Options and What They Mean.

[Mechromancer]

I have found that not many of us know what 2/3rds of our BIOS configurations options mean. I hope this thread will turn into a reference for us all. Let me add, I don't yet know what a lot of these options mean yet myself, but I will edit this thread several times a week until these mystery options are fully explained.

NOTE: I'm basing these on ASUS M3A79-T Deluxe ver.0602 BIOS options. Please confirm you have the same or similar options on your motherboard. Feel free to add your own answers or questions to these and more options in AMD AM2+ bioses.

Here are the "mystery" options that I want to explore in this first installment:

*CPU Configuration*
> ACPI SRAT Table:http://www.techarp.com/showfreebog.a...ng=0&bogno=351

The ACPI Static Resource Affinity Table (SRAT) stores topology information for all the processors and memory, describing the physical locations of the processors and memory in the system. It also describes what memory is hot-pluggable, and what is not.

The operating system scans the ACPI SRAT at boot time and uses the information to better allocate memory and schedule software threads for maximum performance. This BIOS feature controls whether the SRAT is made available to the operating system at boot up, or not.

When enabled, the BIOS will build the Static Resource Affinity Table (SRAT) and allow the operating system to access and use the information to optimize software thread allocation and memory usage.

When disabled, the BIOS will not build the Static Resource Affinity Table (SRAT). Alternative optimizations like Node Memory Interleaving can then be enabled.

If you are using an operating system that supports ACPI SRAT (e.g. Windows Server 2003, Windows XP SP2 with Physical Address Extensions or PAE enabled), it is recommended that you enable this BIOS feature to allow the operating system to dynamically allocate threads and memory according to the SRAT data.

Please note that you must disable Node Memory Interleave if you intend to enable this BIOS feature. Node Memory Interleave is a static optimization that cannot work in tandem with the dynamic optimizations that the operating system can perform using information from the ACPI SRAT.

If you are using an operating system that does not support ACPI SRAT (e.g. Windows 2000, Windows 98 ), it is recommended that you disable this BIOS feature, and possibly enable Node Memory Interleaving instead.

> C1E Support:http://lwn.net/Articles/286432/
This is a power feature that is called the same thing on both Intel and AMD platforms that apparently adds a little more power savings. How you ask? I still do not fully know, but it compliments Cool 'n Quiet it seems.

> AMD Live!:http://experience.amdlive.com/us-en/Home-Page.aspx
Download and try the AMD Live Browser. It is really neat. Past that, I still don't know what the BIOS option actually does, but it may have something to do with some "Away-Mode" which is yet another mystery.

*Chipset>PCI Express Configuration*
Port Features

> Gen2 High Speed Mode:http://forums.extremeoverclocking.co....php?p=3307279
This one is simple. If you have a PCI Express 2.0 card, then ENABLE IT! It comes Disabled for compatibility reasons. Some of us may have an AUTO option that will auto detect as well. Now as other M3A79-T Deluxe owners will see, we have the ports listed from #02 to #12. The manual has these divided into two groups (2,3,11,12) and (4,5,6,7,9,10), and the latter group lacks the Link Width option.

> Link ASPM: Active State Power Management - http://www.microsoft.com/whdc/connect/pci/aspm.mspx
Apparently this has to be the same setting across all port feature groups.

> Link Width: Simply sets PCIe Speed

NB-SB Port Features

People have posted BIOS settings here:http://vip.asus.com/forum/view.aspx?...Language=en-us , http://forums.techpowerup.com/showthread.php?p=885604 , http://forums.amd.com/game/messagevi...hreadid=100542

> NB-SB Link ASPM: Active State Power Management for this link.

> NP NB-SB VC1 Traffic Support: [Enabled] (virtual channel 1) helps with Isochronous Flow-Control Mode & voice over IP. Still needs a bit more clarification.

*Chipset>Hyper Transport Configuration*

> Isochronous Flow-Control Mode:http://cpu-hypertransport.blogspot.c...echnology.html
After reading that, we may have more questions than answers. It goes to show Hyper Transport has an entire community behind it and there are neat features we almost never take the time to access.

> HT Link Tristate: Enable to tristate parts of the link in order to reduce power consumption

> UnitID Clumping: Enable to increase the number of outstanding requests supported by a single device. It may be enabled for PCI-Express GFX links in certain configurations. Clumping may be enabled when using only the lower number bridge within each PCIe GFX core.

> 2x LCLK Mode:http://vip.asus.com/forum/view.aspx?...Language=en-us

This is the best info I could find on the 2x LCLK Mode setting:

This setting only affects HT 3.0 so Phenom's may benefit from it while Athlon's it just does not apply to. LCLK stands for Latency Clock. The 2x means that instead of one full bandwidth HT Link you are requesting two half bandwith HT Links. For performance, at times it is better to have a two lane highway; traffic flowing in both directions at the same time along the same strip of asphalt at 50mph, than it is to have a single lane highway along the same strip of asphalt with traffic lights controling the directional flow at 100mph.

When we have the stability/performance implications of all these options figured out, we maybe we can delve into AMD memory timing configuration options. From what I've read so far, I bet there are truly ways to get more stability and performance at higher clocks out of our HyperTransport-based systems. Check out this HYPER TRANSPORT BLOG: http://cpu-hypertransport.blogspot.com/. TechARP also has their BIOS Optimization Guide that defines pretty much everything else as well: http://www.techarp.com/freebog.aspx

To Google I go!

[Mechromancer]

*Reserved* Memory Timing configurations

[Mechromancer]

*Reserved* Performance and Power testing of all these features

[Particle]

Gen2 High Speed Mode is an easy one. It toggles the use of PCIe 2.0. Disabled means you'll get PCIe 1.0 regardless of what is in the slot. The other options are various ways of enabling 2.0. I think they're presented for reasons of compatibility.

[Oese]

HT Link tristate is an option were the ht link frequency is set to pause in some (i think energy saving) modes i understand..

ht unitID clumping is an option were id's of data units can be packed together to save space in the ht pipeline.. making it possible to have more data in the pipeline..

[Mechromancer]

Whoa. I turned all the features on except for the power saving ones (C1E, ASPM, and Tristate features) and I magically have more performance consistently. When I have time to go feature by feature and figure out what is giving me such a large boost I will post screens and numbers. I think the UnitID Clumping is really boosting graphics performance. The other features under Hyper Transport Configuration have given me a boost in both single and dual threaded performance under Cinebench R10 64bit as well.

Neato!

[informal]

Hmm nice idea for a thread Mechromancer,I'm looking forward to your results .
Many settings in the BIOS are really not that well explained,so a thread like this is welcomed

[roofsniper]

Whoa. I turned all the features on except for the power saving ones (C1E, ASPM, and Tristate features) and I magically have more performance consistently. When I have time to go feature by feature and figure out what is giving me such a large boost I will post screens and numbers. I think the UnitID Clumping is really boosting graphics performance. The other features under Hyper Transport Configuration have given me a boost in both single and dual threaded performance under Cinebench R10 64bit as well.

Neato!

i would be interested in what you did to get better peformance. i really haven't messed with my bios settings much. just the normal voltages, clocks and ram stuff.

[mcbalaban]

Yes! Yes!

I have a A4M79 Dlx waiting at home and will be watching this thread intently!

[Daveburt714]

Mechromancer: Thanks for this thread man, I've been curious about alot of these settings myself. Since I seem to be pretty close to my comfort zone on my OC I'll try playing with them myself. If I find anything interesting I'll be sure to post.

Nice info in those links BTW!

[Kingsfan]

great thread! can't wait to see more

[mAJORD]

Awesome thread.

Hope we can all contribute and learn from it.. Looking fwd to seeing what's boosted your performance.. It could be CPU tweak.

[non]

a nice thread...what good is a good bios if the user can not find the use of it. Just waiting for the acc

[MadDias]

when u hit f4 in the "cpu configuration" menu u get two more options.
one is something like "GART error report" which is explained in the bios. the other one is "microcode updation" which u can only enable or disable without any further explanation. what the heck is microcode updation?

[EniGmA1987]

I am pretty sure microcode updates have to do with CPU errattas and such. It was also thought at one point that we could hack the microcode to enable unlocked (or higher limit) multipliers in AMD CPUs. However that is kinda pointless now because of all the black editions.

Those 2 options are for developers and debugging.

[DarthElvis]

bump-Needs to stay on page 1

[Final8ty]

bump-Needs to stay on page 1

Needs to be a sticky

[Rammsteiner]

If you want, add this for the memory options, although it's a bit vague;

Drive Strengths too loose might kill the signal so the IMC wont be able to receive anything from your RAM. However, if it's too strong it detects too much, also ripple etc, which will cause instability as well. Default settings will work 99.99% of the times, if not, it's due to SPD.

There's 6 Drive Strength's;

DQS, Data, MEMclk, Addr/CMD, CS/ODT and CKE.

It ain't clear what all of these do, however MEMclk does help now and then getting higher Mhz's out of your RAM, Data is a bit weird since I actually gained slight stability be lowering it instead of pushing it, however it seems i9t might help for having large amounts of RAM, just like Addr/CMD. That's more or less for the registers, if you've say 32GB of RAM but it's unstable, try to put it up so it will become stable. CS/ODT, it has to do with on die termination, I guess for the RAM's ODT (not CPU). CKE is some sort of control chip over the DDR2's IC's, no idea how this might help.

ODT, either the CPU's or DIMM's, is some sort of filter for ripple, but when ripple might be in or decreased, I dont know. It's very unclear what exactly everything does, but now and then they certainly do help.

[msimax]

paging TONY

[Rammsteiner]

paging TONY

Great idea

[Meizuman]

NB Power Management Features
Dynamic clock gating for IOC/NT/MCU/CFG.

I would like to know what this is... options are: Auto, Enabled, Disabled.

[Daveburt714]

This thread should definetly be a STICKY!

I'm not a noob, but to be honest I still haven't even figured out what the CPU VDDA does... I've played with it quite a bit and to be honest I get the same results @ 2.8 as I do on AUTO or 2.5....

Some folks swear it needs to be @ 2.8, but I just don't see any difference between the two...

Does anyone know for sure what this setting does? I just haven't seen any real improvement by upping it so I keep it at AUTO..

[kazgirl]

This thread should definetly be a STICKY!

I'm not a noob, but to be honest I still haven't even figured out what the CPU VDDA does... I've played with it quite a bit and to be honest I get the same results @ 2.8 as I do on AUTO or 2.5....

Some folks swear it needs to be @ 2.8, but I just don't see any difference between the two...

Does anyone know for sure what this setting does? I just haven't seen any real improvement by upping it so I keep it at AUTO..

"The CPU power regulation circuitry voltage is determined through the CPU VDDA Voltage option, with a 2.8V maximum."

Taken from this article - http://enthusiast.hardocp.com/articl...50aHVzaWFzdA==

Not a lot of info but it gives you a bit of an idea of what it does...!!

It helps with power regulation, so if you suspect that your OC is failing due to irregular Power supply, then you can try increasing the VDDA to see if it helps with stability...!!

I've found recently that my Phenom 9950 OC's better in Win7 64-bit than it does in Vista SP2 64-bit..!!

In Vista my 9950 max stable is 3.1Ghz @ 1.475v, in Win7 max stable is 3.3Ghz at 1.475v, this is with all settings identical apart from the CPU Multi, 15.5 in Vista and 16.5 in Win7...!!!!

So it seems that the OS implementation is a key factor, given that Win7 is a Beta OS then I would have expected it to be less stable than Vista, but the opposite is true...!!!

[demonkevy666]

hidden potion on *cpu configuration* ebnable/disable microcode update

press F4 it will show up.

that Vc1 NB and SB traffic never made sense to me.

I've tried to get mot of it enable and setup, but I got a no boot a one point. :/

[gOtVoltage]

This thread should definetly be a STICKY!

I'm not a noob, but to be honest I still haven't even figured out what the CPU VDDA does... I've played with it quite a bit and to be honest I get the same results @ 2.8 as I do on AUTO or 2.5....

Some folks swear it needs to be @ 2.8, but I just don't see any difference between the two...

Does anyone know for sure what this setting does? I just haven't seen any real improvement by upping it so I keep it at AUTO..

From what ive found VDD helps alot with the Vdroop under load. If you push the CPU to High Clocks under load it can pull more than the Mobo handles @ 2.5v VDD.. By raising this it allows the Mobo to keep the Volts alittle more stable under Load.

Ive noticed that i can achiece a Higher CPU/Nb when using More VDD . This is with/without ACC.

9950(140watt) torture CPU for Mobo's

Using 2.5VDD my max is 3.45ghz 1.74v@ 2600nb@ 1.662v.
Using 2.8VDD my Max has been 3.6ghz 1.74v@ 2200nb@ 1.662v

3.55ghz @1.74v with 2630nb@ 1.662v..24/7. using 1066mhz on the ram.

I cant wait till i get a AM2/AM3 945/950 to torture on M3A79-T.

So far the mobo/CPU combo is more than proven its self in my hands .


Note:

2xLCLK mode seems to work decent on Phenom .

I believe this keeps the HT more stable. Instead of the HT running Running full steam on 1 lane it cuts it in Half , thus allows 2 lanes vs 1. I guess less bottle necking. This in return would help most with multiple GPU's or anywhere that high data transfers are needed via HT. I believe it even keeps the Sata devices more stable when Overclocking too.

Even @ 2600+ and above it simply works. PHII's can go up to /Above HT3000x2 = 6000+HT ( Xtreme members have already done this) . I am curuiose if 2xLCLK mode helps at such the High of an HT vs not using it at all. It has helped me keep my lowly 9950 chugging along

P.S. when using High TDP Graphics .

Press F4 advanced menu options In HT and or PCI-E.

Lane # 2 and lane # 11 are the 16x width slots .
They are set at 75watts.

When running High TDP cards ive found raising this Value to 200+ or Max 255watts really helps with all Ghraphics cards to overlock them and keep them stable with High HT or high CPU settings.

Example : with 3870x2 on Air factory cooler.



Nice post KazGirl,,

Icouldnt find that VDD info earlier . Thank you and yes Vdd does help especially when running a lower watt PSU.