First post, by Ozzuneoj
- Rank
- l33t
I've been sorting through my huge pile of SIMMs and DIMMs. Many of the sticks aren't labeled with their speed or capacity, so I'm attempting to identify them. The SIMMs are generally easy to figure out... its the 168pin DIMMs that are quite baffling.
I'm finding a surprisingly wide range of speed ratings on the SDRAM chips, and some brands (Samsung) don't even seem to have the ns speed rating on their DRAM chips, at least not in the way others do.
On the sticks marked PC-100 I'm finding markings like these printed near the end of the long part numbers: 8, 8A, 8PC, and on a Samsung "128MB 100Mhz CL3" labeled stick the chips say "022 K4S280832A-TC1L" ... then on a Hyundai PC-100 labeled stick "TC-20S" and on a generic looking "ATL PC100" stick and an "IBM FRU" PC-100 stick there are NEC chips that say "-A10-9JF" toward the end of their part numbers.
I have a ton of un-labeled very low capacity (16MB to 32MB) sticks that have chips with markings like: 10, 10S, 10K, TC-10, T10, G12 (Samsung) and a Samsung stick that has a label that says "32MB SDRAM 9ns" with chips that say "-G10" and don't have a 9 anywhere on them. 😕 10ns should equal 100Mhz... but why do the PC-100 labeled sticks appear to have 8ns chips? The ones marked with "12" may even be 83Mhz rated? Then I find actual 83Mhz rated SDRAM and the chips say -10 on them. 🤣
Marked PC-133 sticks generally say: 7, 75, 7G, 7.5, 7H, and some Hyundai "PC-133 marked" sticks who's chips have no recognizable speed markings, just "HY57V64820HG 005ITA T-H" , and a Kingston ValuRAM PC-133 256MB stick with Hynix chips that say "244A A HY57V56820BT-H". 7.5ns should be 133mhz, so I guess these aren't too mysterious. Are the 7Mhz ones more likely to provide overclocking headroom?
I also have one PNY stick with Toshiba chips that have markings that look more like those of EDO chips "tc51v17805BNTS-60". The 16 chips also only have 28 pins despite being flat like the SDRAM chips on other DIMMs. What kind of board would use 60ns EDO RAM on a 168pin DIMM?
Is there any rhyme or reason to this? I'd love to be able to look at a DRAM stick and identify the capacity and speed capabilities. I've mostly gotten to that point with 30pin and 72pin SIMMs and DIPs, but DIMMs are just all over the place.
Any insight on this situation would be much appreciated. I genuinely want to know how this works.
Also, I was reading recently about "SPD", and I was surprised to see that DIMMs have had this kind of information stored in those tiny little single chips all along. Is there a reliable DOS program that will always 100% read the information contained within these chips? Something like this would certainly help identify preferred RAM settings.
Now for some blitting from the back buffer.
