Changing Ram on Notebook

[FruityComputers]

So today I was just experimenting with a couple of old Panasonic CF-28 Toughbooks and some Ram sticks.

The first Toughbook is the (CF-28 mk1)
The second Toughbook is the (CF-28 mk3)
 
The (CF-28 mk1) has 128MB ram built into it... I put in a 256MB ram stick in and it reads as 256MB total ram. The total Ram should be 384MB so I'm missing 128MB of the ram.

I then took the 256MB ram stick out of the (CF-28 mk1)  and stuck it in the (CF-28 MK3) The CF-28 mk3 has 256MB ram built in so I add the other 256MB and that accepted the ram at a total of 512MB which is correct so there is nothing wrong with the 256MB ram stick.

Heres where it gets interesting.... I decided to try the 512MB ram stick in the (CF-28 mk1)  and it reads 384MB in total? the total should be 640MB of ram.

I decided to remove the 512MB ram stick and I put it in the (CF-28 mk3) given it a total of 768MB of ram. I think thats an impressive result as the CF-28 mk3 is only suppose to accept a maximum of 512MB.

Back to the CF-28 mk1 128 MB + 256 should add to 384 MB ram but = 256 MB ram
Next try with 512 MB + 128 should add 640 MB ram but = 384

Why is this? does the mk1 need a specific ram stick?

The Ram upgrade to the mk3 was successful.

So here are my specs now
Panasonic CF-28 mk3
Ram: 768 MB
Processor: 1 GHz
HDD: 64 GB SSD

As for the mk1 CF-28 I just though it was best to leave it running from the built in ram for now. Why doesn't the ram add up properly on the mk1? I'm pretty sure if I got the right kinda ram then I could upgrade it to a total of 640MB of ram.

Could anybody recommend me of the best Ram for that CF-28 mk1 

Sorry if this is confusing to read


     

[coreplayer2]

When I looked at the specs for this notebook I recall it only accepting 384MB RAM total

[nitram]

Confirm hardware specs via manual, whether the mk1 accepts PC133 or only PC100 RAM. Then look at the fine print on your RAM modules. At first glance both look the same and fit the slot, but if the mk1 only accepts PC100 then PC133 won't be of benefit. You also can't mix and match these. Also some motherboards only accept single sided RAM modules, not double bank, may be why it's only seeing half RAM.

In regards to exceeding maximum reported RAM on the mk3, old manuals only indicate how much RAM worked based on current manufacturing at time of print. For example, if 256 RAM modules were the largest available at print that doesn't necessarily mean a 512 MB module would not work.

The specs on your modded mk3 are nice, you will have no problems running *Core.

[FruityComputers]

The ram I tried was PC-100 256MB "MT16LSDF3264HG-10EE4 PC100-22 US BZABJ1C007 20021 SYNCH 100MHz CL2
I also tried a 256MB PC-133 Infineon HYS64V3222OGDL-7.5-D 32mx64 D4v3d619246 PC133-333-520

Both had the same results with only half the ram stick being recognized.

Whats the difference between high density ram and low density ram?

I can't see any small print on the ram.

[gerald_clark]

Use dmidecode to see what the slots accept, and what they see.

[Juanito]

If you do something like this:

Code: [Select]

$ sudo dmidecode --type memory
..you should see something like this:

Code: [Select]

Handle 0x0046, DMI type 16, 23 bytes
Physical Memory Array
Location: System Board Or Motherboard
Use: System Memory
Error Correction Type: None
Maximum Capacity: 16 GB
Error Information Handle: Not Provided
Number Of Devices: 2

Handle 0x0047, DMI type 17, 34 bytes
Memory Device
Array Handle: 0x0046
Error Information Handle: Not Provided
Total Width: 64 bits
Data Width: 64 bits
Size: 8192 MB
Form Factor: SODIMM
Set: None
Locator: DIMM A
Bank Locator: Not Specified
Type: DDR3
Type Detail: Synchronous
Speed: 1600 MHz
Manufacturer: Samsung
Serial Number: 8FDFC0B8
Asset Tag: 02143000
Part Number: M471B1G73DB0-YK0 
Rank: 2
Configured Clock Speed: 1600 MHz

[FruityComputers]

Update on the CF-28 mk1

I manage to find a compatible 256mb memory stick on ebay which works, the laptop sees all of the ram this time 384MB of ram in total... it just so happened that the seller also sold the same memory in 512mb sizes so I ordered one of those which arrived yesterday and I tried it and that worked so I've now got 640MB in total now.  I had I feeling that it would work. 

[nitram]

Oh what a feeling, awesome!