Dumb thing - and mixing memory PC2100 and PC2700 - and WHAT???

[David W.E. Roberts]

Hi,

O.K. it was a dumb thing to do.

I looked at the specs. and didn't open the box.

So:

I have a Fujitsu Siemens Scaleo L system which came with 128Mb memory, and
seemed to struggle a bit with XP.
I decided to upgrade

The machine has a 2.6GHx Intel Celeron
Accoring to the Intel site
http://www.intel.com/products/desktop/processors/celeron/
the processor has 'up to 400MHz' FSB.

According to the motherboard manual for the ASUS PG4V-FSC (which came with
the system) the DDR DIMM Type for 533MHz FSB is PC2700 or PC2100 and for
400MHZ FSB is PC 2100.

So I ordered 256Mb of PC2100 from Crucial Technology.
At £25.99 +VAT and free delivery it seemed a worthwhile upgrade.

New memory arrives promptly, and I set about swapping stuff - intending to
put the new RAM in Slot 0 because it is the bigger chip (256Mb vs. 128Mb)
and also test the new memory on its own before putting the original 128Mb
chip back.

System is up and running fine with the new memory - it may just be me but it
seems loads quicker.

However looking at the original chip it is labelled as PC2700-25330 256Mb
DDR 333MHz CL2.5

The part number is HYMD232646B8J-J AA-A
Made in Korea by (I think) Hynix

WHAT??????

Only seeing half the memory, and the chip doesn't match the Motherboard
spec.

My original query was going to be "can I safely mix these memories"? but I
have just realised that the DIMM claims to be 256Mb but Belarc Advisor (and
XP and various Linux) all report the memory as 128Mb.

It is also PC2700 when the motherboard manual says PC2100 with 400MHz FSB
and Intel say the Celeron is up to 400 MHz FSB.

Is this a 'can only see half the memory' thing that Crucial talk about?

What is going on?
Wrong sticky label or something more obscure?

Should this original memory have worked?

Any point in putting it back in?

TIA
Dave R
--

 

[David W.E. Roberts]

Hi,

O.K. it was a dumb thing to do.

even dumber - I read the wrong bit of Belarc Advisor and it did show 256Mb
of memory.
It one of my other systems which has 128Mb.

Apologies for the mislead.

So the question now is what I started on:

can I mix PC2100 and PC2700 memory?

TIA
Dave R

 

[David W.E. Roberts]

even dumber - I read the wrong bit of Belarc Advisor and it did show 256Mb
of memory.
It one of my other systems which has 128Mb.

Apologies for the mislead.

So the question now is what I started on:

can I mix PC2100 and PC2700 memory?

Looking at
http://www.crucial.com/uk/kb/answer.asp?qid=4031
the FSB speeds are
133MHz for PC2100 (doubled to 266)
166MHz for PC2700 (doubled to 333)

So what is the correct FSB speed for a 2.6GHz Intel Celeron?
And why does the ASUS manual talk about 400MHZ and 533 MHz FSB?
The further I dig, the deeper I sink!

Help!
Dave R

P.S. Presumably the best thing to do is return the PC2100 and swap for
PC2700?
Faster memory as long as the CPU and Motherboard can utilise this.

 

[~misfit~]

On that system? Yes.

Looking at
http://www.crucial.com/uk/kb/answer.asp?qid=4031
the FSB speeds are
133MHz for PC2100 (doubled to 266)
166MHz for PC2700 (doubled to 333)

So what is the correct FSB speed for a 2.6GHz Intel Celeron?
And why does the ASUS manual talk about 400MHZ and 533 MHz FSB?
The further I dig, the deeper I sink!

The correct FSB for a 2.6Ghz is 100Mhz, 'quad-pumped' (Yuk! market-speak)
and called 400Mhz. Confusing huh? The "533Mhz" they talk about is actually
133Mhz 'quad-pumped'.

AMD double the true Mhz figure (DDR = Dual-Data rate) as the memory can send
a signal on both the rising and falling signal of the FSB. Intel quadruple
the actual FSB speed when the talk about memory as they have 'quad-pumped'
memory busses.

Help!
Dave R

P.S. Presumably the best thing to do is return the PC2100 and swap for
PC2700?

It's up to you, PC2700 is more flexible if you upgrade later or overclock. I
wouldn't buy PC2100 RAM and haven't for ages. PC3200 minimum, it'll run
slower if the bus is set slower no problems and gives you room for upgrading
if you need faster RAM later. Not much price difference either.

Faster memory as long as the CPU and Motherboard can utilise this.

The CPU and mobo will only run it as fast as it's set to, in your case
100Mhz standard. There is actually no advantage in having faster RAM than
the PC2100 that you have, other than the fact that you can run it faster
later if you want to. If you can swap it then I would in your shoes, get
PC2700, the same as the other stick. At least then it's rated up to 166Mhz
in case you want to use it in a faster system.

Make sense? I seem to have rambled a bit but it is 1:38am here.