CF-27 RAM limitation/support problem

I got two SDRAM cards, 64 and 128 which both are 133Mhz. I wanted to upgrade ram to 192 because in manual it says 192 is maximum, but when i installed 128, the bios says only 130 is usable. Because the computer have build-in 64 ram, I can add 64 sdram and the result is 130 but why it can't add full 128? Shouldn't it support 192 or does it require some setups or driver or... what???

 

Check to see if you have the latest bios update for your machine. Sometimes these computers can be a little picky on ram, if you have access to another stick of ram you might want to try that. Also be sure to test the memory, I had a problem that I could not figure out until I ran "memtest86 ver4" and found that I had a stick of bad ram. the program can be downloaded for free from the internet and boots from a floppy.

 

I am not surprised
As KLonsdale suggested check for a bios update
The older models are fussy on ram modules ,and ram upgrades to max are sometimes hit and miss
If yours is a mk-1 it will probability not like pc133 (it came with pc66)
Even the newer model cf-28 in the early versions would accept only pc100 in the larger modules
If you confirm the bios is the latest try 128mb pc100 or pc66 modules

Alex

 

I'm using a PC133 128mb sodimm in my Mk.2 CF-27 which was previously in a Sony Vaio and I get the full 192mb. I think it has something to do with the number of chips on each side as well as the size.

Isn't it something like the ones with 4 chips on each side work but the others don't? I'm sure I read it on here somewhere.

 

Check the chip count on your mk-2 and the OP can compare with his


Alex

 

It's going to be low-density or "JEDEC Standard" RAM; it will have 8 chips per side, double sided. It's available here:

http://www.allmemoryupgrades.com/pc100sodimm.html

Note the photo on the left and the notes below.

The PC100 will work in place of PC66 99% as long as it is low density; it's when you start trying to use high-density RAM that you have problems.

Whatever you do, avoid BZ Boys on eBay; I bought 4 SODIMMS 512MB PC133 supposedly "Low-density". They are one of the few really bad eBay experiences I've had; suffice it to say their product IS NOT as advertised and their support was nonexistent.

mnem <~~~ Memory almost full ~~~<<<

 

Both are high density and the CF-27 is MK2.

 

Nope; the one on the left is low-density. The PC100 JEDEC standard is 8 per side, double-sided on a 256MB. The PC66 JEDEC standard is 8 per side, double-sided on a 128MB; it will LOOK nearly the same if it's newer RAM made using uBGA chips instead of SMD.

The CF-28 Mk1 uses PC-100 RAM, max of 384MB (128MB onboard, plus up to 256MB on 1 expansion slot). I believe Alex is correct in his suggestion that your CF-27 is designed for PC66; that would coincide with the capacities you've given and the relevant JEDEC standards.

mnem
JEDEC, schmEDEC...

 

I meant mine both sdrams I have are high density and my CF-27 is MK2. Also I read that Mk1 uses EDO while all newers are using SDRAM.

 

Correct

Now we need some forum members with mk-2 units with 128mb add-on ram to check the brand and type they are using


Alex

 

According to the Reference Manuals:
MK1- 144Pin SO-DIMM, SD RAM or EDO, 64mb on board, 192mb max.
MK2- 144Pin SO-DIMM, SD RAM , 64mb on board, 192mb max.
Mk3- 144Pin SO-DIMM, SD RAM , 128mb on board, 256mb max.
MK4- 144Pin SO-DIMM, SD RAM , 128mb on board, 256mb max.
I no longer have any CF-27's so I can't check any sticks, but low density seems to be what I used. I don't believe I ever tried it, but it might be worth it to check a 256mb stick in a MK3 or MK4. You might get lucky like we did with exceeding the maximum published ram in the CF-28's.
CAP

 

Hmmmm -

A 128MB PC66 EDO SODIMM... THAT would be a rare bird in the wild. Don't think I've EVER seen one. Seen lots of 64MB... never 128MB.

mnem<~~~ Legacy WetWare ~~~<<<

 

Now I found the reason... or I hope so. I notice that the 64 sdram is in fact 100Mhz and the 128 is 133Mhz. So 133Mhz won't work on cf-27???

 

Not likely - too big a jump in speed; the memory controller can't refresh fast enough... also, MAJOR differences in memory architecture between PC66 & PC133.

Like I said... you're going to have to hunt for that bad boy. Try some PC100 128MB SODIMMs - you may get lucky. They are plentiful & cheap.

mnem
Not without my ankles!

 

I have several CF-27's MK2s and MK4s with 256mb additional ram. All sims have 16 chips. 128 edo does exist. I got one in my CF-25.

 

In PC66?

I doubt it. PC100, SURE... seen lots. Even seen 256MB EDO in that speed...

mnem