Re: P4P800-VM & Kingston HyperX DDR400



In article <449d6122$0$6669$5a62ac22@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>,
"DRS" <drs@xxxxxxxxxxxxxxxxxxxxxx> wrote:

(I'm relaying this for a third party; any and all errors are mine).

Motherboard:

ASUS P4P800-VM Rev 1.xx
BIOS: AMI Version 1008.008
Chipset: Intel i865P/PE/G/i848P Rev A2
Southbridge: Intel 82801EB(ICH5)

RAM:

1. Kingston HyperX DDR-400 Model KHX3200UL/512 2-2-2-5
Note: CPU-Z says this stick only has SPD timings for 200Mhz. Is this an SPD
programming error?

2. Kingston HyperX DDR-400 Model KHX3200UL/512 3-3-3-8
Note: This stick has SPD timings for 200, 166 and 133Mhz.

CPU:

Intel Pentium 4 Northwood 2.80 GHz
(Family) F (Model) 2 (Stepping) 9
(Ext. Family) 0 (Ext. Model) 0 (Revision) D1

Clocks according to CPU-Z 1.34.1:

Core Speed: 2792.9 MHz
Multiplier: x 14.0
FSB: 199.5 MHz
Bus Speed: 798.0 MHz

The problem:

Two sticks of Kingston DDR400 KHX3200UL/512 were purchased some months
apart. If either stick is installed independently the FSB runs at 200Mhz
(DDR400). When both sticks are installed (either in slots 1&3 or 2&4) the
FSB runs at 133Mhz (DDR266). Obviously the goal is to have them both
running at DDR400, even at the slower timings of the older stick. The
system configuration seems to meet the requirements in the manual for
running DDR400. No amount of tweaking the (limited) BIOS options can force
anything other than DDR266 with both sticks installed.

Apart from updating the BIOS to 1018 I've run out of ideas or explanations.

You can decode the SPD with this document:

http://web.archive.org/web/20030417070529/http://www.jedec.org/download/search/4_01_02_04R11A.PDF

If you have a CAS3 module, the SPD will contain the minimum clock cycle
time at CAS2.5 and CAS2.0. In the JEDEC doc, these are "CLX-0.5" and
"CLX-1". For the CAS2 stick, they would have to be CAS1.5 and CAS1.0,
and as far as I know, those don't exist. As a result, a CAS2 stick
would probably only have one set of timings, and the two CLX entries
would be zeroed. The BIOS would know, that for any clock speed below
200MHz, the CAS would remain CAS2 as a minimum. On the other module,
the BIOS knows that at 133Mhz, the slow module can do CAS2.

It almost sounds like it is trying to run both sticks at the fastest
common CAS, rather than the fastest common clock speed. If it did
the latter, you'd be at 200MHz and CAS3, and a lot better off.

Updating the BIOS sounds like an option. If you look at the BIOS
listing, it warns if your current BIOS is before 1008, you should
flash to 1008 as an intermediate point, using PPVM1008.exe inside
the download file for 1008. Presumably that is updating the boot
block. Then follow that with flashing to whatever later version
you want to use.

Paul
.



Relevant Pages

  • Re: RAM SPD problem
    ... Today for the first time I ran the CPU-Z utility and found that, although the SPD of one of these RAM modules shows an RAS# to CAS# delay of 3 for both 166MHz and 200MHz, the other's SPD indicates RAS# to CAS# delays of 11 and 13 respectively. ... Also, with the RAM speed set in the BIOS to Auto, the memory is being run at 333MHz. ... "Command Rate" is a setting that affects how the Address/Command bus ... The DIMM has two busses. ...
    (alt.comp.periphs.mainboard.asus)
  • Re: P4P800se and populating all memory slots?
    ... I've tried using 2x512 basic Crucial modules with 2x512 Samsung ... and take me back to the bios screen). ... it ran the memory ... I'd start by looking at the SPD contents. ...
    (alt.comp.periphs.mainboard.asus)
  • Re: ACTUAL RAM SPEED
    ... The CPU-z memory tab shows '166.7 MHz'. ... Depends on whether you have the BIOS use the SPD settings (what the ... be overclocking your 166MHz memory by running it at 200MHz. ...
    (microsoft.public.windowsxp.hardware)
  • Re: BIOS F7:Optimized Defaults not being accepted
    ... The system seems to be running very stable so I won't be flashing the BIOS and the 4 RAM modules are working fine as well. ... The SPD tab showed some interesting info about the 4 modules of RAM. ... Memory type DDR3 ... Timings table ...
    (microsoft.public.windowsxp.hardware)
  • Re: BIOS F7:Optimized Defaults not being accepted
    ... Memory Size 4096 MBytes ... I don't think the BIOS has done a particularly bad thing in this case. ... you expect every column in the SPD to ... As far as the SPD chips themselves are concerned, ...
    (microsoft.public.windowsxp.hardware)