I have a Sony Vaio PCG-K23 (http://esupport.sony.com/perl/model-news.pl?mdl=PCGK23) which came preinstalled with 2 x 256MB Infineon HYS64D32020GDL-7-B (http://www.datasheetcatalog.com/datasheets_pdf/H/Y/S/6/HYS64D32020GDL-7-B.shtml) PC2100 SO-DIMMs. I recently purchased 2 x 512MB Patriot Memory PSD512333S (http://www.google.co.uk/url?sa=U&start=2&q=http://www.patriotmem.com/products/specs/psd512333s.pdf&e=1102&mr=912,,3B123,!b_U:ablcb) PC2700 SO-DIMMs hoping to replace the Infineon SO-DIMMs and bring it up to the maximum capability of 1GB. I realise that the PC2700 parts will only run at PC2100 speeds so don't worry about that. However when I install the 2 x 512MB parts the laptop (BIOS and Windows) still only reports 512MB.

Lavalys Everest (http://www.lavalys.com/products/overview.php?pid=1&lang=en) reports the following BIOS details:

[ BIOS ]

BIOS Properties:
Vendor Phoenix Technologies LTD
Version R0110X1
Release Date 05/19/2004
Size 512 KB
Boot Devices Floppy Disk, Hard Disk, CD-ROM
Capabilities Flash BIOS, Shadow BIOS, Selectable Boot, EDD, BBS, Smart Battery
Supported Standards DMI, ACPI, ESCD, PnP
Expansion Capabilities PCI, AGP, PCMCIA, USB
and unfortunately I can't find any BIOS update available from Sony. I've tried eSupport (http://www.esupport.com/global/) but they don't say in advance of purchase what BIOS update you are buying for your $30.

I installed one of each SO-DIMMs just to collect the details on them for comparison and Everest gives the following:

SPD Memory Modules:
DIMM1: PDP Systems 512 MB PC2700 DDR SDRAM (2.5-3-3-7 @ 166 MHz) (2.0-3-3-6 @ 133 MHz)
DIMM2: Infineon 64D32020GDL7B 256 MB PC2100 DDR SDRAM (2.5-3-3-7 @ 142 MHz) (2.0-3-3-6 @ 133 MHz)

and


[ DIMM1: PDP Systems (512 MB PC2700 DDR SDRAM) ]

Memory Module Properties:
Module Name PDP Systems
Serial Number None
Module Size 512 MB (1 rank, 4 banks)
Module Type Unbuffered
Memory Type DDR SDRAM
Memory Speed PC2700 (166 MHz)
Module Width 64 bit
Module Voltage SSTL 2.5
Error Detection Method None
Refresh Rate Reduced (7.8 us), Self-Refresh

Memory Timings:
@ 166 MHz 2.5-3-3-7 (CL-RCD-RP-RAS)
@ 133 MHz 2.0-3-3-6 (CL-RCD-RP-RAS)

Memory Module Features:
Early RAS# Precharge Not Supported
Auto-Precharge Not Supported
Precharge All Not Supported
Write1/Read Burst Not Supported
Buffered Address/Control Inputs Not Supported
Registered Address/Control Inputs Not Supported
On-Card PLL (Clock) Not Supported
Buffered DQMB Inputs Not Supported
Registered DQMB Inputs Not Supported
Differential Clock Input Supported
Redundant Row Address Not Supported

[ DIMM2: Infineon 64D32020GDL7B ]

Memory Module Properties:
Module Name Infineon 64D32020GDL7B
Serial Number 010C5B16h
Manufacture Date Week 32 / 2004
Module Size 256 MB (2 ranks, 4 banks)
Module Type Unbuffered
Memory Type DDR SDRAM
Memory Speed PC2100 (133 MHz)
Module Width 64 bit
Module Voltage SSTL 2.5
Error Detection Method None
Refresh Rate Reduced (7.8 us), Self-Refresh

Memory Timings:
@ 142 MHz 2.5-3-3-7 (CL-RCD-RP-RAS)
@ 133 MHz 2.0-3-3-6 (CL-RCD-RP-RAS)

Memory Module Features:
Early RAS# Precharge Supported
Auto-Precharge Not Supported
Precharge All Not Supported
Write1/Read Burst Not Supported
Buffered Address/Control Inputs Not Supported
Registered Address/Control Inputs Not Supported
On-Card PLL (Clock) Not Supported
Buffered DQMB Inputs Not Supported
Registered DQMB Inputs Not Supported
Differential Clock Input Supported
Redundant Row Address Not Supported

Memory Module Manufacturer:
Company Name Infineon Technologies AG
Product Information ...

and the following about the North Bridge:

[ North Bridge: ATI Mobility Radeon 7000 IGP ]

North Bridge Properties:
North Bridge ATI Mobility Radeon 7000 IGP

Memory Timings:
CAS Latency (CL) 2T
RAS To CAS Delay (tRCD) 3T
RAS Precharge (tRP) 3T

Memory Slots:
DRAM Slot #1 256 MB (DDR SDRAM)
DRAM Slot #2 256 MB (DDR SDRAM)
Does anybody know what the problem here might be with the laptop not recognising the full capacity of the 512MB parts? Could it be

The Patriot parts are simply not compatible?
The BIOS needs an upgrade (if so - where would be a good place to get this since I can't get it from Sony)?
The Infineon 2 ranks, 4 banks versus the Patriot 1 rank, 4 banks details above are significant?
The North Bridge/memory controller is limited even though the Sony specs on the laptop claim that up to 1GB of RAM (2 x 512MB) is possible?
Something else?

If anybody needs further technical information feel free to ask and I'll post it. Thanks in advance for any assistance that anybody here can provide on this query.

I think the most likely scenario is 1. Memory is not as compatible as people suppose. I've had situations where SIMMs will just not work with a MOBO. Your best bet is contacting Sony and determining the specs for compatible memory. You might also check www.crucial.com.

Thanks for the prompt response. Unfortunately Sony support don't seem to be too responsive. The laptop was bought in the US but I am in Europe. The US Sony site has not responded to queries and the European one detects that the laptop is a US model and, as such, not supported by the European site. I will try studying the memory specs again to see if I can determine why the Patriot parts might not be compatible. If anybody has suggestions as to what specifically I should be looking for feel free to post them. I just wondered if the "rank" details mentioned above might have been significant?

Try www.crucial.com. Then have a memory finder where you can enter a make and model. Also the Sony should have come with documentation. If you don't have that documentation you should be able to find it on the Sony site.

Hi Scott - yes, I had checked Crucial before and interestingly they suggest some PC2700 parts for the Vaio PCG-K23 upgrade as do some other online memory selectors. See here (http://www.crucial.com/store/listparts.asp?Mfr%2BProductline=Sony%2BVAIO+PCG-K+Models&mfr=Sony&tabid=AM&model=VAIO+PCG-K2x+Models&submit=Go). I would have expected if some PC2700 512MB parts would work then most or all others should too. The general descriptions of the Crucial and Patriot parts are the same (i.e. 512MB • DDR PC2700 • CL=2.5 • UNBUFFERED • NON-ECC • DDR333 • 2.5V • 64Meg x 64). Conversely if there was a problem with the Patriot memory compatibility (whether because it was PC2700 or for some other reason) then I would have expected it not to work at all rather than working but only appearing as if it was 265MB. However I have been unable to ascertain the detailed specs of such ostensibly compatible parts and determine the differences between them and the Patriot parts above. I suppose there are two issues here (a) understanding why the Patriot parts are currently not working or simply incompatible and (b) getting a working upgrade. I'm stuck on (a) and realise that (b) may involve simply buying new compatible memory and somehow offloading, swapping, selling the Patriot parts. Thanks again for your assistance.

By the way - I used the Patriot memory configurator/selector to find memory compatible with the Vaio PCG-K23 and it came up with this PC2100 512MB part (http://www.patriotmem.com/products/specs/psd5122668s.pdf). I bought the PC2700 equivalent (http://www.patriotmem.com/products/specs/psd512333s.pdf) but assumed that this would work albeit at PC2100 speeds. Looking at the respective summary datasheets I can't see any obvious reason as to why they would be significantly different other than being PC2100 versus PC2700 but again (as reported by EVEREST) the PC2100 part is "2 rank, double sided" while the PC2700 part is "1 rank, double sided" so I wonder if the difference in "rank" specification might be the key to why the Vaio only sees 256MB of the 512MB PC2700 part?

I don't know if there would be an obvious reason. I know from my experience that SIMMs with the same specs would not work in the same machine. Could be quality control or other factors.

OK - I will continue to delve into this in an attempt to at least explain the problem (to distract myself from getting annoyed at buying the wrong parts... :( ). I will have a read of the datasheets for the relevant compatible and not fully compatible SO-DIMMs and individual RAM chips to see if I can figure it out and will post back with details if I can figure anything out. Thanks for the help.

Was your problem ever resolved? I am having the same problem and went to crucial to get what I thought was a compatible memory module for my sony pgc-k23.

Never found out precisely why the original DIMMs were incompatible so I just bought more memory that was guaranteed to be compatible and sold the other DIMMs on. I thought that Crucial had a money back guarantee on parts recommended them as compatible that turned out not to be? I think I bought from Crucial in the end too. Can't remember now.

Never found out precisely why the original DIMMs were incompatible so I just bought more memory that was guaranteed to be compatible and sold the other DIMMs on. I thought that Crucial had a money back guarantee on parts recommended them as compatible that turned out not to be? I think I bought from Crucial in the end too. Can't remember now.

Was your issue resolved now? I have just been presented with this exact model laptop by a customer, and I find myself unable to get the memory beyond 512. Any insight would be of great help.

I ended up buying a new pair of 512MB DIMMs from a vendor (Crucial or Kingston I think) who guaranteed compatibility. I could not figure out the specific differences between the compatible DIMMs and the ones that I had bought in the first place. However I think that it was down to bank/rank specifications and/or the way that the physical memory chips were addressed. I also managed to sell on the original DIMMs so that I was not out of pocket.

My recommendation would be to go to one of the well known memory sites (Crucial, Kingston, Patriot Memory etc.) and buy from them or their resellers with a compatibility guarantee or your money back. Taking a chance is just not worth the hassle and possible expense.

By the way - I presume you know that this make/model maxes out at 1GB (2 x 512MB)?

I ended up buying a new pair of 512MB DIMMs from a vendor (Crucial or Kingston I think) who guaranteed compatibility. I could not figure out the specific differences between the compatible DIMMs and the ones that I had bought in the first place. However I think that it was down to bank/rank specifications and/or the way that the physical memory chips were addressed. I also managed to sell on the original DIMMs so that I was not out of pocket.

My recommendation would be to go to one of the well known memory sites (Crucial, Kingston, Patriot Memory etc.) and buy from them or their resellers with a compatibility guarantee or your money back. Taking a chance is just not worth the hassle and possible expense.

By the way - I presume you know that this make/model maxes out at 1GB (2 x 512MB)?

Yeah I already checked max memory at crucial, but was apprehensive about ordering considering you and many others also have this issue. The customer brought me "value select" Corsair memory asking for me to install it. As reported, it won't recognize beyond 448, I'll recommend to her that we purchase from crucial.

Thanks for the help.