Ron Posted September 17, 2001 Share Posted September 17, 2001 I upgraded the OS on my system (PII300) a couple weeks ago to Win2K with no problems but realized pretty quick the 64M of ram wouldn't cut it, so I bought a 256M stick and plugged it in. All good, no problems, except I got tired of watching the ram count everytime I booted up and decided to remove the old ram sticks, 2x32PC66. However, next time I started up the graphics on the desktop were corrupted and the cursor left a persitent black trail behind it. I removed the video drivers for my TNT2Ultra and reinstalled, even tried different drivers but still had the same problem. It only corrected itself when in VGA mode, which wasn't acceptable. Pondering a bit I decided to plug in one of the old ram sticks again. Wonders be told, the corruption was gone and hasn't come back. :confused: I can live with the 288M ram count now, but I am left wondering the why's and wherefore's. I would much appreciate enlightenment, as technical as possible, from a knowledgeable person. Muchas gracias in advance. Ron 0 Quote Link to comment Share on other sites More sharing options...
Schrullenhaft Posted September 17, 2001 Share Posted September 17, 2001 That does sound strange and I wouldn't know exactly why it happened. I can only guess that the new DIMM didn't exactly cooperate with the AGP slot (since they're all tied to the same bus). What DIMM slot was the 256Mb module sitting in and did you move it around when you reinstalled the 2 x 32Mb DIMMs ? What were the parameters and brand of your new memory module (CL=?, PCxxx, Unbuffered or ECC, etc.) ? If you swap the DIMM locations around will the problem come back ? It's possible that adjusting some memory timings or AGP features in the CMOS/BIOS setup may alleviate the problem. Settings like "UC" or "UCSW" for the AGP slot may be changed around or possibly the "AGP or Graphics Aperture" size could be adjusted (increased ?). The UC or UCSW setting may have the biggest effect on your problem (I suggest possibly using "UC"). I assume that your new memory is faster than your old DIMMs and it is possible that your motherboard is somewhat unstable with the higher memory speed (which may be automatically set by the SPD ROM on some memory modules). When you're old PC66 memory is installed the memory is set for a higher latency (lower speed), thus a more stable performance. However this is a bit unlikely. Sometimes a BIOS update for the motherboard may fix this. Some motherboards also don't "cooperate" very well with certain brands or certain sizes of memory. Due to the age of your computer I wouldn't assume that it would have a "Fast Write" capability in the AGP bus, which could also be a factor. [ 09-16-2001: Message edited by: Schrullenhaft ] 0 Quote Link to comment Share on other sites More sharing options...
rleete Posted September 17, 2001 Share Posted September 17, 2001 On older MB, the single DIMM must be in the first slot. Try putting the large one in there, and removing the smaller ones. If the first slot is left open, it defaults to settings which may not be compatible with the RAM. Otherwise, it uses the settings reported by the RAM itself. 0 Quote Link to comment Share on other sites More sharing options...
Ron Posted September 17, 2001 Author Share Posted September 17, 2001 Thanks Schrullenhaft, I have the 256M DIMM in Bank 0 already. No, I haven't experimented by placing it in different banks, I will try that but am not too confident of that doing anything. My system is a Dell and the BIOS features aren't very detailed, I flashed it to the latest version A09. The aperture size for AGP is set at 64M, with an option to 256M, I am unfamiliar with what this setting actually does, will have to investigate. Side band is enabled, but no 'Fast Writes', it is AGP Ver.1. Bus speed is 67MHz with data transfer at 134MHz. The specs for the new DIMM are as follows, funny the prog Dimm_ID couldn't identify it, saying 'unknown', I used Sandra, : Xerox 256M 16x(16Mx8) SDRAM CL3 PC133U-333-542. The old DIMM is : Micron (id#) 32M 16x(2Mx8) SDRAM CL3 PC100-333-7501. I am not sure of the accuracy of the PC100 designation for this DIMM. There is a further BIOS update from Intel for this MB but it isn't compatible with the existing Dell one. Thanks again, Ron 0 Quote Link to comment Share on other sites More sharing options...
Schrullenhaft Posted September 17, 2001 Share Posted September 17, 2001 Generally the AGP Aperture should be set to 'half' of system RAM; in your case 128 should be appropriate. However I couldn't really imagine that would change anything in regards to your particular problem. Both your new and old memory appear to be CAS/CL 3. I'm not exactly familiar with the numbers reported after the '333' and what their bearing may be on memory timing. I assume that you're installing the two 32Mb DIMMs in sockets 1 & 2, behind the 256Mb DIMM in socket 0, is that correct ? If you're truly curious you may want to pull all but one of the 32Mb DIMMs (i.e. - leaving a single 32Mb DIMM in socket 0) and see if your problem occurs again. Usually motherboards have a problem addressing multiple banks of RAM rather than just a single or double bank of RAM. Maybe your motherboard has a problem with the 256Mb DIMM being double-banked, while the 32Mb DIMMs are single-banked. Check out your documentation to see if it mentions anything about placement of DIMMs in regards to the number of 'banks' or 'single-sided/double-sided'. I can't think exactly why more DIMMs would be more stable since it is a higher load, electrically speaking, for the chipset and power supply to drive. Hopefully a BIOS update should help, but most likely it won't address this particular problem which probably remains one of electrical/electronic design. How much newer is the Intel BIOS compared to the Dell BIOS ? Was it an Intel warning not to flash OEM-branded Intel motherboards with the Intel BIOS ? I'm guessing that it would actually still work (it would just say Intel instead of Dell on the initial BIOS splash screen), but it may not be worth the hassle to find out. 0 Quote Link to comment Share on other sites More sharing options...
Mal Elder Posted September 19, 2001 Share Posted September 19, 2001 Just to add a little bit, you can have some real problems setting your AGP aperture size too big... from the MS support site... http://support.microsoft.com/directory/article.asp?ID=KB;EN-US;Q253912 Basically mentions that you have a limited amount of memory usable by the system, and setting your aperture size to something big eats up that memory. I had mine set to 128 megs and had all sorts of random blue screens (in vcache, for you techy folks). Dropping down to 64 cleared up all my issues (: Just FYI if you start playing with it... 0 Quote Link to comment Share on other sites More sharing options...
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