This is my own personal public service announcement for any owners of the CUSL2 series boards. I want to thank Stormblade5000 for introducing this information on the www.cusl2.com board. This message is being posted to multiple locations, and I hope that anyone that finds this will forward it to other people in the hopes that information eventually reaches Asus' cryptic technical support department (which seems to be hidden in the 9th circle of hell).
The issue at hand is the memory handling of this board. Basically every CUSL2 owner knows that this board is picky when it comes to memory -- but I never knew until a very short while ago how picky. Any CUSL2 owner who has at least 1 ATA/66 drive should at least heed this message. I currently have 3 ATA/100 drives, and I cringe when I think about what has happened to my data over the past 4 months. It doesn't matter if you're running Intel's Ultra ATA Storage Driver, or just have Microsoft's DMA mode enabled in your system settings -- I had this problem in both situations.
The CUSL2 has a memory limitation of 512MB. Intel also states that there is a limitation of at most 2 double-sided DIMMs when running at PC133. (ie, 4 "sides" of memory)
Most people that have memory problems with this board tend to find out very quickly. There is massive instability, it doesn't POST, you can't install anything, etc.
It has always come highly recommended that you use name brand memory with this board. People with generic memory tend to find problems no matter what memory configuration they have.
Knowing this, in July of 2000, I purchased my CUSL2 with 256MB of Micron PC133 CAS3 memory. The memory was in the form of 2 double sided 128MB dimms. This is within the specification of the motherboard, and Intel's 815E specification. Here's the tricky part -- my system was completely stable until about October of 2000.
THE PROBLEM
It was at this point that I started to notice more frequent crashes. I don't remember how I found this out, but I started to notice data corruption occuring when I transferred information across my drives in DMA mode. I also started to notice "memory burps." For example, a file would pass a CRC check the first time through, fail it a second, and then pass the third and fourth (or some combination thereof).
At this point, I became horrified of the fact that I had defragmented my disks numerous times since July. But I still had no idea where the data corruption was coming from. I then started to get freezes occasionally when transferring large files in DMA mode. I tried swapping the memory in different locations, different slots, BUT I NEVER tried taking out of the DIMMs.
When I got home from college, I tried different DMA cables, transfers between different drives, I upgraded my OS from 98SE to Windows 2000. I was rock-solid in 2000, but I still had the data integrity issues.
It was at this point that I read Stormblade5000's post on the CUSL2 board. I have 2 double sided DIMMs -- which is within the specification of the CUSL2. I've been stable for a very long time, I just have a data corruption problem when transferring large files (or any files really) across the disks at incredibly high speeds. So, I took both my DIMMs to be hardware tested at a local store -- both passed without a single error.
THE SOLUTION
To cut to the point: having only 1 128MB PC133 DIMM solved my data integrity problem. The problem that was posted on the CUSL2 board was that the CUSL2 becomes unstable whenever you use more than 3 "sides" of memory. My memory was listed as "TESTED" with the 815E, which may have been why I had less crashes than someone with generic memory, but the board just couldn't hold up when the memory started being stressed with ATA/100 transfers.
So, basically, in order to ensure 100% stability and reliability, I'd say never use more than 3 "sides" of memory in the 3 DIMM slots if you're going to run at PC133. For example, you can have 3 SINGLE-SIDED 128MB DIMMs, or a double-sided DIMM and ONE single-sided DIMM.
In my 2 double-sided DIMM memory configurations, both of my DIMMs tested out 100% ok with software and hardware testers. The only catch was this (and I never found this out until I installed Norton Utilities 2001): after doing an intensive DMA transfer, I would get a memory failure at a random address somewhere on the second side of the second DIMM (no matter what memory configuration/DIMM order). Basically it was an offset greater than 192,000,000. If I rebooted, and re-ran the test, it would run 100% ok on any pattern.
I've ordered 1 Crucial CAS2 256MB DIMM to replace my 2 Micron PC133 DIMMs. Since I tested my board with just 1 Micron DIMM, I'm assuming that the Crucial 256MB DIMM (double sided or not -- I'm only going to be using 1 slot) will be just as reliable.
Even if you think your system is stable, I urge anyone with at least 1 ATA/66 drive to do some serious data stress tests on your system. Get a program like WinSFV that makes MD5 CRCs of your files and start copying GIGS (yes, GIGS) of data across your drives. Ensure that you're not getting corruption somewhere along the way. Your memory configuration may be fine when it comes to everyday applications or games, but like me, it didn't hold up when it comes to ATA intensive transfers.
I have roughly 100GB of storage across my 3 drives, and over the past 6 months, I've transferred probably close to 600GB across my disks (2 at the time, now 3). I cringe when I think about what might have happened to my data as it was being burned to CD, copied from one disk to another, copied from one disk to the same, and defragmented. I'm not sure if the corruption occurs when the data transfer rate is low (like with burning a CD, etc), but I can't find out now.
I hope this helps some of you out there, and I urge all of you to do some serious data-integrity stress tests on your system.
ceraph
The issue at hand is the memory handling of this board. Basically every CUSL2 owner knows that this board is picky when it comes to memory -- but I never knew until a very short while ago how picky. Any CUSL2 owner who has at least 1 ATA/66 drive should at least heed this message. I currently have 3 ATA/100 drives, and I cringe when I think about what has happened to my data over the past 4 months. It doesn't matter if you're running Intel's Ultra ATA Storage Driver, or just have Microsoft's DMA mode enabled in your system settings -- I had this problem in both situations.
The CUSL2 has a memory limitation of 512MB. Intel also states that there is a limitation of at most 2 double-sided DIMMs when running at PC133. (ie, 4 "sides" of memory)
Most people that have memory problems with this board tend to find out very quickly. There is massive instability, it doesn't POST, you can't install anything, etc.
It has always come highly recommended that you use name brand memory with this board. People with generic memory tend to find problems no matter what memory configuration they have.
Knowing this, in July of 2000, I purchased my CUSL2 with 256MB of Micron PC133 CAS3 memory. The memory was in the form of 2 double sided 128MB dimms. This is within the specification of the motherboard, and Intel's 815E specification. Here's the tricky part -- my system was completely stable until about October of 2000.
THE PROBLEM
It was at this point that I started to notice more frequent crashes. I don't remember how I found this out, but I started to notice data corruption occuring when I transferred information across my drives in DMA mode. I also started to notice "memory burps." For example, a file would pass a CRC check the first time through, fail it a second, and then pass the third and fourth (or some combination thereof).
At this point, I became horrified of the fact that I had defragmented my disks numerous times since July. But I still had no idea where the data corruption was coming from. I then started to get freezes occasionally when transferring large files in DMA mode. I tried swapping the memory in different locations, different slots, BUT I NEVER tried taking out of the DIMMs.
When I got home from college, I tried different DMA cables, transfers between different drives, I upgraded my OS from 98SE to Windows 2000. I was rock-solid in 2000, but I still had the data integrity issues.
It was at this point that I read Stormblade5000's post on the CUSL2 board. I have 2 double sided DIMMs -- which is within the specification of the CUSL2. I've been stable for a very long time, I just have a data corruption problem when transferring large files (or any files really) across the disks at incredibly high speeds. So, I took both my DIMMs to be hardware tested at a local store -- both passed without a single error.
THE SOLUTION
To cut to the point: having only 1 128MB PC133 DIMM solved my data integrity problem. The problem that was posted on the CUSL2 board was that the CUSL2 becomes unstable whenever you use more than 3 "sides" of memory. My memory was listed as "TESTED" with the 815E, which may have been why I had less crashes than someone with generic memory, but the board just couldn't hold up when the memory started being stressed with ATA/100 transfers.
So, basically, in order to ensure 100% stability and reliability, I'd say never use more than 3 "sides" of memory in the 3 DIMM slots if you're going to run at PC133. For example, you can have 3 SINGLE-SIDED 128MB DIMMs, or a double-sided DIMM and ONE single-sided DIMM.
In my 2 double-sided DIMM memory configurations, both of my DIMMs tested out 100% ok with software and hardware testers. The only catch was this (and I never found this out until I installed Norton Utilities 2001): after doing an intensive DMA transfer, I would get a memory failure at a random address somewhere on the second side of the second DIMM (no matter what memory configuration/DIMM order). Basically it was an offset greater than 192,000,000. If I rebooted, and re-ran the test, it would run 100% ok on any pattern.
I've ordered 1 Crucial CAS2 256MB DIMM to replace my 2 Micron PC133 DIMMs. Since I tested my board with just 1 Micron DIMM, I'm assuming that the Crucial 256MB DIMM (double sided or not -- I'm only going to be using 1 slot) will be just as reliable.
Even if you think your system is stable, I urge anyone with at least 1 ATA/66 drive to do some serious data stress tests on your system. Get a program like WinSFV that makes MD5 CRCs of your files and start copying GIGS (yes, GIGS) of data across your drives. Ensure that you're not getting corruption somewhere along the way. Your memory configuration may be fine when it comes to everyday applications or games, but like me, it didn't hold up when it comes to ATA intensive transfers.
I have roughly 100GB of storage across my 3 drives, and over the past 6 months, I've transferred probably close to 600GB across my disks (2 at the time, now 3). I cringe when I think about what might have happened to my data as it was being burned to CD, copied from one disk to another, copied from one disk to the same, and defragmented. I'm not sure if the corruption occurs when the data transfer rate is low (like with burning a CD, etc), but I can't find out now.
I hope this helps some of you out there, and I urge all of you to do some serious data-integrity stress tests on your system.
ceraph