SPD incorrectly reports DDR400 as DDR266

[dkathrens77]

I have an Abit IS-20 motherboard in a freebie box someone gave me.
It has an Intel i865 chipset.

I decided to max out the RAM, and bought two 1 Meg sticks of clearly labeled used DDR400 to put in it.

The machine correctly senses 2 gigs of RAM, but insists it is DDR266 instead of DDR400.

I'm going to take the extra step of trying each stick separately (they are not same mfr)
and see if that identifies one as the culprit.

I paid some $58 apiece for these sticks...don't want to go running back to the seller
with my gun half cocked.

There are settings in the BIOS for RAM timing...I can de-select "set by SPD" and wing it, but don't understand what, if anything can be changed to get the max speed from my RAM

Any advice would be appreciated.

 

[jaquith]

Welcome to Tom's Forums!

Look at the Memory -tab then take the DRAM Frequency {I/O bus clock} X 2 = Running Speed {Data rate}. If you don't set the DRAM Frequency in the BIOS is runs at slower BIOS 'Default' Speed.

Go into the BIOS, Set DRAM Frequency -> DDR-400, I too would recommend setting the CAS Timings according to the Mfg's spec, and to be safe set the DRAM Voltage -> 'Spec'.

 

[jb6684]

Does either stick get recognized as DDR-400 ?

Reason I ask is in the older Intel processors the CPU limited the RAM speed. What CPU do you have?

 

[jaquith]

http://www.abit.com.tw/test_report/IS-20/02.php
http://www.abit.com.tw/page/en/motherboard/motherboard_detail.php?DEFTITLE=Y&fMTYPE=Socket%20478&pMODEL_NAME=IS-20

Seem like DDR-400 is the limit. Looked at manual; see DRAM Timing Selectable in BIOS {Speed, Timings}.

 

[dkathrens77]

http://www.abit.com.tw/test_report/IS-20/02.php
http://www.abit.com.tw/page/en/motherboard/motherboard_detail.php?DEFTITLE=Y&fMTYPE=Socket%20478&pMODEL_NAME=IS-20

Seem like DDR-400 is the limit. Looked at manual; see DRAM Timing Selectable in BIOS {Speed, Timings}.

OK, I tried each stick separately. here are some data

Stick 1

GPM400X64C3/1G/K

Chips are Samsung (didn't copy chip numbers yet)

Installed singly, (Slot 0) reports DDR266

MemTest+ reports CAS 2-2-2-6


Stick 2

VPM400X64C3/1G/K

Chips are Princeton PT7021ADX8SCYU5T

Installed singly, (Slot 0) reports DDR266

MemTest+ reports CAS 2.5-3-3-6


I went into BIOS to manually set the RAM timing to match the
lower set of numbers (2-2-2-6)

But this still causes the machine to report DDR266

jaquith I will search for these settings again in BIOS.

Thanks all for quick responses.

 

[jb6684]

Hmmm, what CPU do you have?

It's been a long time since I've seen any DDR but, your CPU Not motherboard settings or the RAM itself will ultimately limit RAM speed....

But I could be wrong it's been what a decade ?

 

[dkathrens77]

Hmmm, what CPU do you have?

It's been a long time since I've seen any DDR but, your CPU Not motherboard settings or the RAM itself will ultimately limit RAM speed....

But I could be wrong it's been what a decade ?

Sorry, it's a Socket 478 Pentium 4 processor. 2.60 GHz

Yeah it's old, but the price was right. It can do what I want done.

And it DID run DDR400 on the OLD RAM that came with it.

I've lookded again at the BIOS (Phoenix AwardBIOS)

The only RAM settings I can manually set are
under "Advanced Chipset Features"

like I said before, I set the numbers to match the slower timings.

I should have written down the names of these settings, darn it.

"stuff like" precharge delays, CAS before RAS delay, etc.

2-2-2-6

 

[jaquith]

I went into BIOS to manually set the RAM timing to match the
lower set of numbers (2-2-2-6).

When mixing RAM, the opposite you need to use the slowest values.
266 CAS 2.0-2-2-6
266 CAS 2.5-3-3-6
=============
266 CAS 2.5-3-3-6

While I appreciate the 266 MHz CAS timings, I haven't a clue what the 'correct' 400 MHz CAS timings are, they're typically higher.

JEDEC 400 MHz possible timings:
2.5-3-3
3-3-3
3-4-4

You, again need to:
DRAM Timing Selectable in BIOS {Speed, Timings}.

Afterwards, what is listed on the following tab:

 

[dkathrens77]

This is a surprise.

You show a screen shot of CPU-Z. I've heard of it, it's for tweaking stuff for overclocking & etc.

Are you suggesting I download/install this? Can I use it to change my DRAM Speed?

I don't know why it changed just because I changed RAM. As stated previously, it WAS running DDR400
with the RAM that was in it originally

Thanks for the tip about using the slowest numbers. I'll try that.

BUT I don't see anything in my BIOS for DRAM Speed.

 

[jaquith]

CPU-Z is free and it's a read-only App used to get info only. http://www.cpuid.com/softwares/cpu-z.html

The example above, 533 X 2= 1066 MHz.

I looked again in your manual, I seem to be mistaken, DRAM Timing Selectable reads the 'SPD' info off the RAM. I don't see where you can set the 400 MHz -- so if it worked before, swap the DIMM Slots 1->2 & 2->1 maybe it'll read the other stick and pull the Frequency higher.

Keep in mind the difference between 266->400 isn't 36% -- it's more like 1~3% max.