RAM questions... Mixing Timing & Max Capacity

[Tsuioku]

Mixing RAM Timings
If the timings of RAM Modules are different, would it cause any problems? Is there anything I need to adjust in the BIOS?

Current scenario... Just recently opened up my T43 and noticed that the two RAM modules have slightly different timings even though they are both IBM FRUs...
Under Keyboard - Samsung 4-4-4-10, 1.8V, 512MB
Bottom of T43 - Infineon 4-4-4-11, 1.8V, 512MB

I am thinking about swapping out one of the modules to a 2GB but most of the modules I see are 4-4-4-12... Would this be ok? Recommended slot as to where I should install it?
What about a 3-3-3-8? Any BIOS adjustments needed?

Max RAM Capacity
Lastly, on paper, it is stated that the max RAM capacity of the T43 is 2GB but I am reading mixed comments that it can go to 3GB since it's more of a Windows limitation while others say Windows will only display/use 2GB if you look at system properties. Can somebody confirm this?

[ajkula66]

Whether a T43/p will take a 2GB DIMM is a hit or miss. I've seen both responses in action-some refusing to boot, and others booting and showing 2.5 or 3GB in BIOS. Since these machines utilize dual channel RAM, you want to have both slots populated, regardless of total amount of RAM installed.

With that said, the chipset limitation is still 2GB, so whatever you have "extra" will remain unused.

http://www.intel.com/products/notebook/ ... erview.htm

[sjthinkpader]

T43/p uses PC2-4200 with 4-4-4 timing, not quite sure what the tRAS is set at
http://www.tomshardware.com/forum/55024 ... ad-posting
(section 9)

Each module model is spec at minimum timing, in this case Samsung at 10 clock cycles and Infineon at 11 cycles until data out from RAS active. But that doesn't mean the system will use it at that. It just means the module is capable of performing at that speed.

If you examine the memory module SPD data, sometimes the parameter are not even coded. So the system has no way of knowing what are in the socket when it attempt to read SPD data at boot time. Then it just use the default speed or do a quick speed test.

It would be best to have a matching pair and some very fast RAM. But T43/p will not run at speed faster than PC2-4200 (4-4-4) anyway. tRAS is one of these fewest occurring timing, only at the beginning of memory access and again when it ran to end of the column address range (FFFF..). tCAS or CL is much more important because there are many more of these occurring.

Most what you can buy today are PC2-5300 DDR2 RAM, which is faster than what the T43/p will use.

There are somethings that don't improve much, for instance:
PC2-4200, 266Mhz, CL=4 yields 15nSec from CAS active
PC2-5300, 333Mhz, CL=5 also yields 15nSec from CAS active
So there are no improvement when system only reading one byte from memory. It will be faster when the system reads many bytes out of PC2-5300 than PC2-4200.

[Tsuioku]

Whether a T43/p will take a 2GB DIMM is a hit or miss.

Do you happen to recall if this applies to all 915 Chipsets or only the GM? (I have the PM) Brands/Models of successful installations? BIOS Differences?


@ sjthinkpader: Good to know that the specs are the minimum settings. Looks like 3-3-3-8 is fine as long as my T43 can take a 2GB module. Just ran CPUz and my T43 appears to be running at 4-4-4-12 so no issue there... but no SPD data was detected.

[sjthinkpader]

The T43/p can take 2x2GB modules logically. But some modules may exceed some parameters such as input capacitance, especially on 16 chip versions. In that case then 16 chips + 8 chips will work.

[ajkula66]

Tsuioku wrote:

Do you happen to recall if this applies to all 915 Chipsets or only the GM? (I have the PM) Brands/Models of successful installations? BIOS Differences?

Applies to both PM and GM.

[Tsuioku]

2 x 1GB it is then... Thanks.

There are somethings that don't improve much, for instance:
PC2-4200, 266Mhz, CL=4 yields 15nSec from CAS active
PC2-5300, 333Mhz, CL=5 also yields 15nSec from CAS active

Just re-read that post and got me thinking... since the actual access period is the same, wouldn't 5300/CL5 technically work in a T43 or will the different SPD cause the T43 to not like it? Chip density?
I have run a search and saw that pianowizard states that it is compatible in one thread while several other members are against it in others.

Main reasons I'm curious is that I found a vendor selling 5300 SODIMMs at a lower price ($16-20) with better chips (Elpida, Micron..) compared to his 4200 SODIMMs ($25 with Samsung or Hynix chips)

[Harryc]

PC2-5300 will work in a T43 or R52. I use it all the time, granted I only use high quality Crucial. In fact if you go to the Crucial page/memory selector program it recommends PC2-5300 for a T43.

[ajkula66]

I doubt that you'll find anyone on this forum, with possible exception of Brad and underclocker, who has gone through more T43/p units than myself, including examples that were never meant to leave the labs but ended up in my quarters anyway....

Never have I noticed any difference in performance-or anything else for that fact-between PC4200-2 and PC5300 sticks in these machines, and I've likely exhausted all combinations possible a couple of years ago.

Spending a couple of extra bucks on a stick of RAM with pedigree makes sense in my book, but you're the only true master of your spending account.

[Tsuioku]

I'll take that as a yes that 5300 modules work in T43s lol...

There may be a little misunderstanding here...
5300 SODIMM = Better chips (Elpida or Micron) at a lower price
4200 SODIMM = Decent chips (Samsung or Hynix) at a higher price.

Like you, I'm more concerned about getting quality RAM. Only worried about grabbing something that isn't compatible.
Just so happens in this case that it's also better quality at a lower cost so somewhat of a no-brainer.

Seeing that you recommended Elpida in another recent thread... I'll probably grab the same.

[sjthinkpader]

Elpida, Micron, Samsung and Hynix are all equal in quality. Generally Samsung will be 6 month earlier in shipping the latest speed grade.

T43 will run the RAM at PC2-4200 speed no matter what you put in it. Since RAM don't generate clock themselves, and take whatever the system sends them; PC2-5300 RAM will run at PC2-4200 speed in T43.

[jheis]

Out of curiosity, how does PNY ram compare.

I have two T43s & recently bought two 2 GB (2x1GB) PNY "Optima" DDR2 PC2-5300 kits of off Amazon.
($32.24 ea set with free shipping) One set has PNY labeled chips and the second set arrived in PNY packaging, but has Hynix chips. Both seem to pass MemTest just fine.

James

[sjthinkpader]

PNY is a module assembler. DRAM are from several sources even when marked PNY. Some manufacturers such as PowerChip will do custom marking. I would not hesitate to use them.

[krayzie]

I run 2x 1GB Kingston Hyper X PC-5300 667Mhz 4-4-4-12 Elpida chips and my T43 sets them to 3-4-4-10