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Click to See Complete Forum and Search --> : MOBO or PC-100 problem? (Both/Other/None/Me)


Fernando
01-12-2000, 07:28 AM
Hi

After an exam on my 128Mb SDRAM DIMM module [made of 8ns SDRAMs (Micron MT 48LC8M8A2TG -8E B) over a 6-layered plastic thing (with a EEPROM labeled ATMEL842 24CO2N SC27 B and a white sticker PC-100 Q-16SD64] I recovered my stamina to fight against this thing again...

Ten months ago I've builtd a PC with a SOYO-5ehm MOBO (bios eh-1be3), a K62 350 Mhz and a DIMM 128 Mb SDRAM (Other peripherals: Alsound 100 ISA 16 bits soundcard; Zoltrix ISA 33600 voice modem; Creative Labs AGP RIVA TNT videocard). Problem is I can't make my memory run at CPU bus clock (i.e. 100 Mhz), it only boots at AGP clock speed (66 Mhz) and, at that speed, it works OK. But I bought a Super7 system (changing my Cyrix on Socket7) and pay for PC-100 memory for running my RAM at 100 Mhz, so I feel in trouble, and a bit upset indeed.

At CPU bus speed (from 75 to 100 Mhz, JP9:2-3 & JP10:1-2) it never boots, just plain black monitor, three lights at keyboard on, and after some seconds starts the beeps (no particular number of sounds, just keep sounding). But at AGP bus speed (JP9:1-2 & JP10:2-3) things change: at 66 Mhz all fine; running it at 75 MHz (with CPU bus clock at 112) it boots but then hangs when starting Win98 (flickering video, I suppose due to AGP overclocking).

I checked every CPU-AGP-SDRAM speed combination. So, I concluded that mine was a fake PC-100 SDRAM, uncapable of booting at 100 Mhz (not even at 83Mhz!!!). But also it seems I can't get my SDRAM boot at CPU speed, only at AGP speed (that's a 1-2 2-3 1-2 configuration of JP7, JP9 & JP10).

Award BIOS [that lacks CAS/RAS and all those things, just "Normal"/"Fast"/"Turbo"/"SDRAM 10 ns"/"SDRAM 8ns"] "autodetects" the SDRAM as 10 ns (when SDRAM running at 66Mhz), but when I change this to "SDRAM 8 ns" hangs when trying to autodetect IDE drives (after memory checking)

I checked the manual and jumpers more than once. Installed ETEQ drivers OK. Changed DIMM port: same thing. SOYO tech-support said "Yours is no PC-100 memory". Components reseller (Microwave Direct somewhere in CA) said only stupid things during several weeks for not having to get back my money (after buying components, and before checking all, my big mistake, I get back to Argentina so forget returns).

So:
¿Any ideas?
¿Some BIOS configuration I may be wrong?
¿How much "performance" do you think I'm losing because of this? ¿Do you think it worths investing (a whole lot of money for me) in a new DIMM?

Thank you VERY much.

Fernando

Target
01-12-2000, 08:07 AM
Could be that you got a DIMM that was marked as PC100 compliant when in fact its not.

If needed, email me and I will send you a program you can run that will tell you what your DIMM is and the speed its rated for/capable of. Its really small progie (10k) and is called DIMM-ID. The associated readme file for the program is 32k <lol>.

You might want to check though and make sure that you didn't miss a jumper setting on your mobo, or double check that you have them set correctly. I know that is the obvious and you said you have done so, but I have personally made mistakes in indentifying how the jumpers were to be configured and its easy to mis-identify them or the pin orientation. You might also want to make sure that your DIMM voltage jumpers are set correctly if you have them on that board.