Vaio Z - VGN-Z710DD RAM Upgrade Confusion

I am hoping to find some help regarding a RAM upgrade from 4gig to 8gig for this unit. From what I am able to tell this unit is basically a Z790 prebuilt for the Canadian market.

I have read the posts on here, but I am confused as to what works. I need the RAM to be able to run a couple of virtual machines for some testing that I am doing.

I am running the R4043M3 bios which enables the VT capability.

If what I have read is correct, it appears that with some of the older BIOS versions there was a limitation as to which DIMM stcks would work.

It now appears that with the newer BIOS and newer 4 gig sticks I should be ok with most DIMMS as long as they support the correct voltage 1.5v and timings 7-7-7-20 (PC8500). The only chips I can find at my local retailers all have 8 chips per side.

Can anyone confirm this for me? Thanks in advance for your help.

 

http://forum.notebookreview.com/sony/480610-sony-vaio-z-vgn-591u-w-8gb-ram-3.html#post6930818

I have a second gen VGN-Z and bought myself 2x 4GB Samsung sticks, each with 8 chips per side. Technically, any stick SHOULD work provided it was made recently (sometime this year maybe). There were reports of some 8x chipped sticks not working because of what seems to be older, more power-hungry chips. The Samsung sticks I bought have the RoHS and ECO labelling stuff on it; not as demanding in terms of power.

As for why older 4x chips-per-side sticks have always worked; they have less chips thus less power demand (which is what myself and numerous other individuals here have concluded with)

And as for which BIOS firmwares to avoid, the R30??M3 (?? being a version number). Those apparently prevent 8GB from working / showing up in the BIOS, thus also in the OS.

...I bought my two sticks for around US$110. But then I bought it as bulk through a contact in Samsung's Engineering dept. You can find it for around that price in Korea if you know where to look mind you.

Mine were supposed to be PC3-8500S (as per the label) but CPU-Z shows PC3-8500F. No idea what the differences are but the sticks ARE genuine (very important), and they are working as they should so I've got no complaints.

 

In short, for DDR3, the letter position equals the CAS latency minus one. F is the sixth letter, so PC3-8500F and DDR3-1066F means CAS 7, like most[*] DDR3 1066 notebook RAM.

8500S is likely a marketing term (it could mean that it uses SPD to set the speed and not Intel XMP for dynamic overclocking. Which is a good thing for you, as the Z doesn't support XMP). Or it could possibly allude to the modules being 7-7-7-20 (S being the 19th letter, so 20).


[*]: I have 8500D, which is CAS 5. But you can't get those bigger than 2 GB per module, for 4 GB total in a Z.