How can you tell the difference between pc66 and pc100 RAM?

[Mears]

Subject sums it up.

 

[bacillus]

you could try using CTSPD!

 

[AndyHui]

There are a few ways to tell.

Look at the memory chips. If they have a -12ns or -10ns rating, they are almost certainly PC66 SDRAM.

Secondly, most PC66 SDRAM lacks the EEPROM or SPD chip. Simply look in the top corner of the DIMM. On most PC100, all PC133 and all DDR SDRAM, there is a small 8-pin chip located in the top corner of the DIMM. This chip is missing on PC66 SDRAM.