What do all these memory related BIOS settings actually mean and do!?

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As discussed in another post, I recently put together a new PC with
the ASUS A8N-E Motherboard.  The MB has the NVIDIA nForce 4 Ultra chip
set, and a Phoenix-Award BIOS (Phoenix - AwardBIOS v6.00PG, 04/07/06,
also listed as ASUS A8N-E ACPI BIOS Revision 1013).  The processor is
the AMD Athlon 64 3500+, External clock 200 MHz.  Memory:  1 Gig of
Corsair Memory CMX512-3200C2PT (2 x  500 Meg DDR 400 chips)

Unfortunately, the manual that comes with the board does not clearly
explain several key BIOS parameters related to system performance.  I
have searched the ASUS, AMD, NVIDIA, and Phoenix-Award web sites in
vain for detailed discussion.

I am not looking to overclock the CPU -- I have no desire to risk
overheating -- but I do want to be sure I am getting the optimum
performance from the RAM and system bus.  I am hoping that someone can
either offer explanations of what these various parameters below mean,
or can steer me to a document that has a reasonably detailed
discussion of both what the parameters, what their interactions are,
and especially what are the safe and unsafe settings for them.

The BIOS options that seem like they are probably relevant are the
following:

DRAM configuration
Max Memclock.  Options: DDR 200 DDR 266 DDR 333 DDR 400 DDR 400 DDR
433 DDR 466 . DDR 500 DDR 533 DDR 550 DDR 600
1T/2T memory timing.  Options: 1T/2T
CAS latency.  Options are Auto 2.0 2.5 3.0
RAS to CAS delay.  Options:  auto 2 3 4 5 6 7
Min RAS active time.   Options:  Auto 5 6 7 8 9 10 11 12 13 14 15
Row Precharge Time.  Options:  auto 2 3 4 5 6
Master ECC enabled.  Options:  disabled enabled
Hyper transport frequency.  Options:  Auto 1x 2x … 5x
Overclock profile.  Options:  Manual / auto / standard / AI overclock
/ AI N.O.S.

For manual overclocking:
CPU frequency  [set at 200 by default]
PCI express clock:  100 MHz up to 145 MHz
CPU multiplier: x4 up to x20
N.O.S.  Option:  Disable Overclock 3% 5% 8% 10%

Thanks in advance for all replies.

Steve O.

"Spying On The College Of Your Choice" -- How to pick the college that is the
Best Match for a high school student's needs.
www.SpyingOnTheCollegeOfYourChoice.com

Re: What do all these memory related BIOS settings actually mean and do!?

Off-topic cross post that could have been kept in the immediately
prior cross post about the same subject.

See also:
Message-ID: <ggp4c2h7nr854uvpn5elvv3nk3it95imn2 4ax.com>
 

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As discussed in another post, I recently put together a new PC with
the ASUS A8N-E Motherboard.  

<Snip>

Thanks in advance for all replies.

Steve O.

"Spying On The College Of Your Choice" -- How to pick the college that is the
Best Match for a high school student's needs.
www.SpyingOnTheCollegeOfYourChoice.com



Re: What do all these memory related BIOS settings actually mean and do!?


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You get to like that or lump it.

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Makes a lot more sense to start a new thread.



Re: What do all these memory related BIOS settings actually mean and do!?


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Is that worse than repetitively making top-posts which quote the entire
header?

<SNIP>>
--
Rgds, George Macdonald

Re: What do all these memory related BIOS settings actually mean and do!?

Yes.


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Subject: Re: What do all these memory related BIOS settings actually mean and
do!?
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On Sat, 22 Jul 2006 23:24:16 GMT, John Doe <jdoe usenetlove.invalid> wrote:

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Is that worse than repetitively making top-posts which quote the entire
header?

<SNIP>>
--
Rgds, George Macdonald



Re: What do all these memory related BIOS settings actually mean and do!?


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Ah so only you are allowed to pollute.  It must be utterly horrid being
you.

--
Rgds, George Macdonald

Re: What do all these memory related BIOS settings actually mean and do!?

wrote:

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He wastes less bandwidth and is easier to read than
you-who-top-post-including-all-headers-for-who-knows-why. :P


--
A Lost Angel, fallen from heaven
Lost in dreams, Lost in aspirations,
Lost to the world, Lost to myself

Re: What do all these memory related BIOS settings actually mean and do!?

Your opinion is duly noted.


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do!?
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On Sat, 22 Jul 2006 23:24:16 GMT, John Doe <jdoe usenetlove.invalid>
wrote:

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He wastes less bandwidth and is easier to read than
you-who-top-post-including-all-headers-for-who-knows-why. :P


--
A Lost Angel, fallen from heaven
Lost in dreams, Lost in aspirations,
Lost to the world, Lost to myself



Re: What do all these memory related BIOS settings actually mean and do!?

wrote:

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Somebody must have left the troll-bait out overnight, and now look
what's happened.

Hey, what's your favorite kind of fan?

max


Re: What do all these memory related BIOS settings actually mean and do!?

That's one of the problems with cross posting.


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do!?
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On Sat, 22 Jul 2006 23:24:16 GMT, John Doe <jdoe usenetlove.invalid>
wrote:

Quoted text here. Click to load it

Somebody must have left the troll-bait out overnight, and now look
what's happened.

Hey, what's your favorite kind of fan?

max




Re: What do all these memory related BIOS settings actually mean and do!?

wrote:

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Most boards nowadays (except OEM targeted models) have these
features, but they are deliberately set to defaults which
might be conservative, but nevertheless are your best bet
for proper system operation

In other words, unless you knew a specific setting you
needed to change, you should resist the urge to change any.
Through experience changing them you might gain more insight
into potential problems, but along with this comes knowing
how to find and resolve problems resulting from changing the
settings.

Finally, the performance gain is usually small, in the grand
scheme of things seeing that technology improves towards a
certain % improvement over time, the amount of benefit you
get from the tweaks is only a few "weeks".  Hardly worth the
possible problems unless this is only an experimental system
rather than one relied upon for primary use.  With that in
mind...


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Overheating is easily pinpointed, but instability can be
more troublesome.  Changing the bios settings can in effect
be overclocking the particular parameter, or the per-board
setting threshold for stability may be exceeded.


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That's easy enough, set the memory bios setting to
"Auto/SPD".   The bus speed is fixed until you want to
changen the CPU speed which you already decided not to do.

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http://www.adriansrojakpot.com/Speed_Demonz/BIOS_Guide/BIOS_Guide_Index.htm


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The safe setting is the default.  The unsafe is to make any
changes to any settings you don't understand or aren't able
to troubleshoot per correct operation.  In other words,
don't change anything until you know what and why you need
to change it.  If there was significant "free" performance
to be gained by just tapping a couple keyboard keys without
further issues, they'd be set that way by default (and
indeed, some may be already, but on the other hand some
changes you make can lower the performance instead).







Re: What do all these memory related BIOS settings actually mean and do!?


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That is mutually contradictory. If the settings are conservative, by definition
that is not necessarily the best bet for proper system operation.

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Nothing like the same thing.

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It isnt necessarily a trial and error thing.

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Gets sillier by the minute.

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Or it may well be a setting that is fine for the particular
hardware used but which isnt the default setting.

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But the RAM parameters arent necessarily.

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You havent established that they arent
understood with better documentation.

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It aint necessarily about troubleshooting, just using particularly
the memory timing parameters that the manufacturer has stated
that the particular memory being used is guaranteed to work at.

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And he asked about that knowledge.

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Wrong if for example the parameters in the spd are
incorrect or the bios doesnt actually drive the ram
with the parameters that the spds say it can do.

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Waffle.



Re: What do all these memory related BIOS settings actually mean and do!?

On Sun, 23 Jul 2006 11:43:09 +1000, "Rod Speed"

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Quite wrong, the best bet is always the most conservative
one.  The bet with the highest payoff, entails the higher
risk.

There's an old saying, "IF you have to ask..."

Re: What do all these memory related BIOS settings actually mean and do!?


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We'll see...


Quite wrong. That wont give the best performance by definition.

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Quite wrong, ALL you need to do is ensure that you are
still operating within the parameters that the hardware
manufacture has guaranteed the device will operate with.

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Just more mindlessly superficial silly stuff.



Re: What do all these memory related BIOS settings actually mean and do!?


Steven O. wrote:
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Yep, they never do. They hope you either leave them alone, or know what
exactly you're changing.


I
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I perfer Auto everything unless I'm Really Sure the board isn't setting
things properly. (Meaning almost never)

If you want to set other settings, you have to do research on what
memory you're using. Here's yours. Lower is faster.

http://www.corsairmemory.com/corsair/products/specs/cmx512-3200c2.pdf

Latency 2-3-3-6 (Intel)
Latency 2.5-3-3-6 (AMD)

2 - CAS Latency
3 - RAS to CAS
3 - RAS Precharge
6 - Active to Precharge

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This one's easy enough. You want DDR400. (It's what your memory is)

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Re: What do all these memory related BIOS settings actually mean and do!?


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Well, fortunately you chose to list the easy ones.

In terms of AMD documentation, document 26094.pdf from AMD contains
info on S754/S939/S940. The AM2 processors get a brand new version
(32559.pdf). Both documents are "BIOS and Kernel Developeršs Guide".

http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/26094.pdf
http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/32559.pdf

Chapter 4 of 26094.pdf contains a bit of info on memory settings.

Max Memclock - That is determined by the rating of your RAM. For
               PC3200 RAM, DDR400 would be the right setting. The
               nearest divisor is selected, to delivering the
               right speed, always erring on the low side. Note -
               the memory gets overclocked when the CPU_clock is
               increased, so turn the memory down proportionally.
               I.e. CPU 200MHz to 250MHz, change DIMM from DDR400
               to DDR333.

1T/2T - These determine the "command rate". When the bus is heavily
        loaded, or if the memory clock is very fast (say DDR600), the
        address value being sent to the memory, needs more setup time
        to clock. If you select "2T", the address is presented for two
        clock cycles, and the info is strobed into the memory on the
        second cycle. 1T is suitable for a double sided DIMM per
        channel, running at DDR400. With four DIMMs (two per channel),
        you could try DDR333 1T or DDR400 2T etc. Using 2T is a 20%
        memory bandwidth penalty. But when the memory just isn't stable,
        2T is one way to fix it.

CAS latency           CAS
RAS to CAS delay     tRCD
Min RAS active time  tRAS
Row Precharge Time   tRP

These are the fundamental timing parameters of the DDR memory. CAS
latency has the largest effect on performance. Generally you set these
according to the parameters provided by your DIMM manufacturer. If
your memory has 2-2-2-5 timings, then those four numbers are the ones
you'll be using. "Auto" should extract those numbers from the SPD chip
on the DIMM. Or you can enter them manually. And if the memory is not
stable, really loose timing would be 3-4-4-8.

See slide 24 here, for the parameter order, which is different than
the order they appear in the BIOS screen:

http://corsairmicro.com/corsair/products/tech/memory_basics/153707/index.html

You can review what "Auto" does for these settings, with CPUZ:
http://www.cpuid.com/cpuz.php

Master ECC enabled - suitable if you have a memory product with ECC on it.
                     Enabling this setting will expose other settings, such
                     as scrubbing and the like.

Hyper transport frequency - CPU_Clock times this number, gives bus clock.
                            Bus clock should be less than or equal to 1000.
                            200 x 5 is the default.
                            If you overclocked to 250MHz CPU clock, use x4.
                            With a CPU clock of 333MHz, use x3, and so on.

Overclock Profile - Generally, on Asus boards I recommend "Manual", as that
                    exposes more settings. The overclock settings tend to
                    be crap (you can do better by setting it up yourself).
                    On some Asus motherboards (like some Intel ones),
                    the "Standard" setting enables PAT (not a feature on
                    AMD boards).

CPU frequency  [set at 200 by default]
   Used if you want to overclock (since multiplier options are limited)

PCI express clock:  100 MHz up to 145 MHz
   Plenty fast at 100MHz. Sure, you can overclock the PCI Express interface,
   but the difference might only show up in benchmarks. (And for any
   board, consult the private forums, for info on which overclocking
   options screw up SATA disks - always use a "disposable" boot disk
   when fooling around!)

CPU multiplier: x4 up to x20
   Rules vary by processor family. On an Athlon64, say at 1800MHz, the
   multiplier might be 9 and may allow setting to a lower value but not
   a higher value. On a FX57, it might be unlocked. I don't know the
   rules, and generally the rules are not stated in AMD docs. For an
   Athlon64, that leaves the CPU clock as the overclocking tool (but
   requires adjusting the HT multiplier and perhaps the DIMM setting).

N.O.S.  Option:  Disable Overclock 3% 5% 8% 10%
   Just another overclocking option. Leave it disabled and DIY.

And after two years of Athlon64, there are plenty of web pages
containing hands-on experience with all these settings and more.
Try http://www.xtremesystems.org/forums/index.php for example.

HTH,
     Paul

Re: What do all these memory related BIOS settings actually mean and do!?


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The others have already given the details or provided links to do so.
But honestly, I wouldn't really bother because from my experience
tweaking memory settings on the A64 (I use the A8N as well), even
though you might get improvements on benchmarks, doesn't really do
anything much for actual performance. Better to use that time to enjoy
doing stuff like surf your favourite site or something :P

--
A Lost Angel, fallen from heaven
Lost in dreams, Lost in aspirations,
Lost to the world, Lost to myself

Re: What do all these memory related BIOS settings actually mean and do!?


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Explaining the details of, e.g. memory timings, is way beyond the scope of
a mbrd manual.  If you want to learn more go DL and read Micron's Data
Sheets on DDR-DRAM chips and DIMMs.

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With few exceptions, the Auto setting in BIOS gets the correct values for
the above settings from the SPD on the DIMM.  It *is* worth checking though
that nothing is wildly off - occasionally a BIOS may get it wrong or a DIMM
mfr may not have qualified his settings with your particular chipset/CPU.

If you haven't already, get Prime95 from
http://www.mersenne.org/freesoft.htm and run the Torture test for an hour
or so, to be sure your memory is working right.  Only then should you try
any tweaking but the only thing I try is the 1T command rate -- most BIOSs
set it to 2T for safety -- and then run Prime95 again.

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IME auto overclocking doesn't work.  Like you I'm not interested anyway, so
set to manual and leave everything at base values.

The only other thing I'd look at is getting Cool'n'Quiet working: enable it
(don't recall which section it's in) and then in the Hardware Monitor
section, enable Q-Fan which will allow you to set a target temp below which
CPU fan speed will be reduced.  Then install the latest CPU driver from AMD
and set the Windows Power Scheme in the Power Option Control Panel to
Minimal Power Management.

--
Rgds, George Macdonald

Re: What do all these memory related BIOS settings actually mean and do!?

http://www.adriansrojakpot.com/Speed_Demonz/BIOS_Guide/BIOS_Guide_Index.htm



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the Best Match for a high school student's needs.
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