SD-RAM types, All backward compatible ??

[Bojo]

Ok all you hardware freiks here's an easy one (or maybe not I dunno),

I am wondering whether my old LX-440B motherboard can handle the newer PC-133 MHZ RAM. Also will it mix with my older RAM? I dunno. Also can I stick a 128MB stick in with my two existing 32MB sticks? in the manual it only talks about 64MB sticks but I'd guess that it might work anyway.

Thanks for your knowledge.

 

[Peter]

Speedwise, no problem. Any SDRAM will work at lower speeds than what its rating suggests.

However, modern SDRAM has a much higher bits-per-chip count, and older chipsets may be unable to handle that. Like Intel BX and LX can't handle any 256-MBit SDRAMs, and only some 128-MBit ones. And even with compatible ones, an old BIOS might be too stupid to actually set them up right.

Technically, a 128-MByte DIMM with 8 chips on it (thus using 128-MBit SDRAM chips) should work.

Regards, Peter

 

[BobK2]

Regarding 256MB sticks: unless ABIT is lying, my BF6 (BX chipset), with three slots, should be able to accommodate three 256MB sticks of memory (for a total of 768MB).

I had previously thought that you cant mix and match memory stick sizes. Dont they all have to be the same size? I dont think you can put a 128 with two 32s.

 

[Sunny129]

Peter,

correct me if i'm wrong, but isnt the amount of memory ona stick of RAM measured in bytes, not bits? a CPU looks to the L1 and L2 caches (measured in kilobytes), then the RAM (in megabytes), and then to the harddrive (in gigabytes) when looking to process information. Or are you not refering to the actual memory capacity of a 128 MB or 256 MB stick of RAM?

 

[Henry Kuo]

if the manual says it can only handle 64MB memory, there is no way you can get the 128MB SDRAM to run at 128MB. it will either be recognised as 64MB or it doesn't boot. Also, some old board can't detect high density memory, which means if you put in a 64MB memory, it will detect it as 1/4 the size, which is 16MB.

Yes, I think Peter meant to say megabyte?

 

[AndyHui]

No, Peter is correct.

SDRAM chips themselves come in different densities. Check out 128MB DIMMs. Some are double sided, some are single sided. The capacity, or density of each discrete chip on a single sided 128MB SDRAM DIMMs is higher than that of double sided 128MB DIMMs....ie they can cram more RAM onto a single chip.

Older chipsets such as the LX, BX and i810 cannot handle high density 256 megabit RAM. The i815E/i815EP can handle it.

Check out Intel's Chipset Comparison chart.