First post, by amadeus777999
- Rank
- Oldbie
After a lengthy back and forth I ordered a 40 piece-batch of 32K/"12ns" srams(supposed vendor: Winbond) from China.
The seller was on ebay, creatively named "adeleparts", with a price less then 1 Euro per chip. Having read Feiopa's quite interesting thread on his "10ns haul" I was prepared for whatever may come.
The low price per item furthermore diminished any artificially high expectations. For comparison - a german seller on ebay had 5 pieces of UM61256AK-12 each one costing around €8(bought all of them nonetheless to have at least some reliable tag rams).
After inserting them in 3 different boards(4+1, 8+1,16+2) and spending as much as 12hours+ on a "sram rat race" of sorts, I can only partially "recommend" them. The biggest pain in the angus being no consistent performance. A few chips were dead(no problem) but one had to pick and try for hours on end to reach a stable result...
Is there any more reliable vendor out there?
On my next purchase I have set my sight on the €2 mark per chip which seems to be a bit more realistic to be able to acquire a somewhat more consistent quality of goods.
I've spotted, supposed, "Alliance" srams on utsource(https://www.utsource.net/itm/p/400243.html) and after an inquiry(which is hopefully not binding) I got a price of 98$ per 50 items - which I deem more than acceptable.
Any recommendations/ideas/experiences?
SoSo:
The HOT433 complained 5 out of 6 times about bad cache and refused to work properly. Luck had it that one 8 chip crew was stable and gave great results in speedsys(all settings maxed out). Unfortunately I flashed the bios and "successfully" locked myself out of the system(keyboard won't work anymore) so further testing has to be postponed.
Benign question: Can I hot-flash the SST5V-eeprom in my LuckStar board without frying it?
The Good:
Finally, I have one board, a single bank'd LuckyStar "dwarf", running with 4 handpicked chips from the bunch and it runs on maximum settings at 50mhz fsb.(WriteThrough since I have 32MB installed).
It is, like the HOT433, a little screamer.(The most aggressive settings(2-1-2) were not stable with the 15ns 64k chips I had initially installed.)
After running the board with Doom, Quake, Win98(Winbench98 & SiSoft) all day I deem it semi-stable.
Update:
Well, tried equipping the SI5PI again and it works now!
I looked at the underside of the remaining chips and took all from the batch ending in "BE"(14) plus two of "CE". Funny thing is that after equipping the board with 12ns srams Doom/II's timedemos run a few tics faster(and yes I have taken the caching delays into account). I also put in two Winbond 16k tag rams which despite the manuals statings does work(as far as I remember up to 512K cache).
Had the board running Quake, Doom, Winbench and so far it's looking ok. Semi-stable.
Verdict:
If you're on a budget or just want to try some sram, this cheapo purchase is pretty much ok. The srams, or some of them, are indeed "tighter" than 15ns BUT in no way reliable in huge numbers and when pushed. Spare boards or slow speeds may not need any better though. Update: test more and take the price of less than 1$ per piece into account... hard to beat. Let's see how long they last running id's infamous "gut-wrenchers".
Background:
Due to a Doom benchmark comparison I was "gearing up" on parts that may help to fully unleash a 486's/classic Pentium's potential to perform.
