Ram problem on P4B533

[marzio biella]

I just got a P4 2.66b for my Asus P4B533 and out of the box it goes up to
3.5Ghz (50deg C full load, default voltage, woohooh, can't complain .
I did the pin#6 trick to have a 3:4 ram multiplier above 133MHz FSB so I can
crank the ram up to 400mhz plus. I have two Samsung 400mhz dimms and if I
only put ONE in I can push the ram over 430mhz (860ddr), but if I put both
dimms I can't even run 400mhz stable so I have to drop the ram down to
325mhz. Aaaaargh. Anyone solved a similar problem? BTW, I chose all the
slowest ram settings.

TIA,
Muntz

 

[Paul]

I just got a P4 2.66b for my Asus P4B533 and out of the box it goes up to
3.5Ghz (50deg C full load, default voltage, woohooh, can't complain .
I did the pin#6 trick to have a 3:4 ram multiplier above 133MHz FSB so I can
crank the ram up to 400mhz plus. I have two Samsung 400mhz dimms and if I
only put ONE in I can push the ram over 430mhz (860ddr), but if I put both
dimms I can't even run 400mhz stable so I have to drop the ram down to
325mhz. Aaaaargh. Anyone solved a similar problem? BTW, I chose all the
slowest ram settings.

TIA,
Muntz

On the non-FSB800 motherboards, it is normal to only be able to use
one double sided DIMM at DDR400 rates. Getting two to work would be
questionable, and might depend on how well the characteristics of
the DIMMs match the motherboard. Since it is partially a loading
issue, you can run two single sided DIMMs at DDR400, but of course
that doesn't allow you to get a larger amount of RAM.

The 845PE/845E only have drive signals for four sides of RAM, and
that is why the socket population patterns are so weird. Ideally
with two sticks of RAM, they should go in slots 1 and 3, but on
your board that isn't possible. Two double sided can go into slot
1 and slot 2, and that isn't the best pattern for overclocking.

About the only thing I can suggest is wait for proper 1GB DDR400
memory to show up and then use just one DIMM. This is a DIMM that
uses (16) x8 chips, where each chip is 64Mx8 (512 Megabits).
An example would be this Kingston module:

http://www.valueram.com/datasheets/KVR400X64C3A_1G.pdf (3-3-3 $572)

There are plenty of products that contain the term
"Stacked 64Mx4 chips", but these put more load than a normal
double sided DIMM on your motherboard. While these DIMMs are
cheaper, I wouldn't expect them to overclock, or even work
at their rated speed for that matter. The description of the
DIMM should say 64Mx8 and not contain the word "stacked" in it.
Stacked chips have two memory ICs in the same package. In some
cases, you can see two pieces of plastic riding on top of
one another, while others put the two die in the same plastic
package.

These Samsung M368L2923xxx modules, at CC or C4 speed grades, are still
listed as "Customer Samples" and not "Mass Production". These are
1GB DIMMs that use 64Mx8 chips. They have had that status for close
to a year.

http://www.samsung.com/us/Products/Semiconductor/DRAM/
http://www.samsung.com/us/Products/Semiconductor/common/product_list.aspx?family_cd=DRM030202

HTH,
Paul

 

[Muntz]

Thank you very very much.
I think that's exactly what I'm gonna do. I'll have a chance very soon to
swap my dimms for one 512MB dimm. I'll do that. Not quite a GB, but should
do for a while.

The 845PE/845E only have drive signals for four sides of RAM, and
that is why the socket population patterns are so weird. Ideally
with two sticks of RAM, they should go in slots 1 and 3, but on
your board that isn't possible. Two double sided can go into slot
1 and slot 2, and that isn't the best pattern for overclocking.

You're right about it being impossible (slots 1 and 3), but why is that?

 

[Paul]

Thank you very very much.
I think that's exactly what I'm gonna do. I'll have a chance very soon to
swap my dimms for one 512MB dimm. I'll do that. Not quite a GB, but should
do for a while.



You're right about it being impossible (slots 1 and 3), but why is that?

If you look in the manual, it will tell you that you can use DS + DS
in slot 1 and 2 and nothing in 3. Or DS + SS + SS in slot 1, 2, and 3.
The manual doesn't mention what happens with other combinations.
Maybe the BIOS isn't too bright and cannot tolerate a space between
DIMMs ?

There are drive signals for four banks on the 845, and three DIMM slots
have a total of six banks on them. By cross wiring slot 2 and slot 3,
they both feed on the same control signals, and if both slots 2 and 3
get single sided DIMMs, they each get to use their own unique control
signal. Sticking a double sided in slots 1 and 3 should work, because
that is no different than putting a double sided in slots 1 and 2.
So, about the only thing left would be a BIOS issue of some kind...

You can try slot 1 and slot 3, to see if it would work, but it still
won't be enough to enable a spectacular overclock. Trying a larger
single DIMM stands a better chance.

Paul

 

[Muntz]

Muchas muchas gracias. All makes sense.
You wouldn't by any chance have heard about enabling hyperthreading on a non
HT P4. Every thread I've ever read had come up empty. It seems to be
hardcoded into the chip. But I haven't scoured the forums at all the techie
sites in a few months. You haven't by any chance heard anything to the
contrary lately?

TIA
Muntz

 

[Robert Hancock]

I don't think there's any way to unlock HT on a chip that doesn't officially
support it. If there was I think it would be pretty well known by now..