Archived from groups: alt.comp.periphs.mainboard.asus (
More info?)
I did ask the question and i can't thank you enough! Sorry about the delay
in my response, just got back from a friends.
"John Hollingsworth" <jwh@cix.co.uk> wrote in message
news:memo.20040913122144.2344E@jwh.compulink.co.uk...
> In article <nospam-1309040611470001@192.168.1.177>, nospam@needed.com
> (Paul) wrote:
>
>> In article <vUa1d.20104$et4.4654@newssvr29.news.prodigy.com>, "Craig"
>> <cpaoli@pacbell.net> wrote:
>>
>> > I am trying to figure out how to set up my a8v for aggressive memory
>> > timings and maybe a mild overclock. I am unfamiliar with this bios,
>> > I have had Abit in the past. What ever happened to the good old days
>> > when you could recognize where to put 2-2-2-6, T1 settings? I have
>> > been to Rojak's but it's just too much. Anyone know where to find a
>> > guide for the a8v v2.0? Thanks in advance!
>> >
>> > Fx53
>> > Corsair 3200 Twin XL
>>
>> This is the BIOS writer's guide for Athlon64. It has a section with the
>> timing parameters. Not all of the AMD timing parameters are a function
>> of the memory - some are specific to the motherboard implementation.
>> Those would best be left at auto. (Pg.81)
>> http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/
>> 26094.PDF
>>
>> Here is a sample memory datasheet. There are five figures of read
>> and write cycles at the end of the datasheet. There is a table of
>> timing numbers (in nanoseconds - these have to be converted to
>> clocks at 5 nanoseconds apiece). Notice how some of the timing
>> parameters are interdependent - one timing parameter must be
>> greater than the sum of a couple of others. This means you cannot
>> arbitrarily crank down the numbers. If you do crank down the numbers,
>> I think the burst of data can be aborted, and the memory bandwidth
>> suffers. (Possibly a low Tras will do that.)
>>
>> (pg.58 DDR400 3-3-3 timings, figures pg.77-81)
>>
http://download.micron.com/pdf/datasheets/dram/ddr/256MBDDRx4x8x16.pdf
>>
>> I have yet to see an authoritative description of setting timing
>> parameters, so I hope the above two docs will give you some hints
>> as to how it works.
>>
>> At PC3200 (DDR400), the definition of the SPD EEPROM is covered by
>> the standards. That means the proper timing should already be there
>> without having to set it. (I.e. Corsair would have put DDR400 timings
>> in the SPD on the memory DIMM. For PC3500, PC3700, PC4000, this is
>> normally not the case, and it is possible for those sticks, the SPD
>> is still set to numbers appropriate for PC3200/DDR400. In those cases
>> it is up to the user to set the timings.) Perhaps a Windows utility
>> like CPUZ or Sandra, can verify that you've already got 2-2-2-6 ? If
>> that is the case, it is pretty hard to twist the knob much tighter
>> than that
>>
>> If you are cranking the FSB, you'll have to back off on the timing
>> numbers a bit. A good place to start, is changing Trcd from 2 to 3,
>> as that is one way to encourage a higher clock. You should also set
>> Vdimm according to the manufacturer's voltage limits - overvolting
>> memory that cannot take it, is an expensive mistake.
>>
>> Check a review site like Anandtech, for recommendations on Tras.
>> Wesley Fink usually runs tests to determine the range of numbers
>> which give good bandwidth numbers. A higher number can sometimes
>> be better, but it is a function of the chipset/BIOS, so someone
>> else's experimental results are a good source of info.
>>
>>
http://www.anandtech.com/mb/showdoc.aspx?i=2128&p=5
>>
>> HTH,
>> Paul
>>
> I didn't ask the question but that information is very useful, thanks
>
> John
>
> Please remove "NO-SPAM" if sending email.
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