I added 2 additional sticks of PC133 memory to a Soyo SY-6BA+IV MB and it causes 2 different games to lock up whereas with only 2 sticks the games were alright.

I ran 2 different memory testing programs (Doc Memory V2 and Mem386 Test V3) over 24 hours with each program and everything passed!

I tried the 2 additional sticks by themselves and all was fine. I tried the 2 sticks in slots 3 & 4 bythemselves and still fine. All sticks are PC133 I believe (not all the same manufacture), though the MB is PC100.

I then tried one additional stick and it was a borderline case. The games would usually work but with a struggle. As I was just over the limit.

The P/S is only a 250W, but the Porcessor is only a PII 450! Nothing overclocked! The videocard is a nVidea GeForce 2 MX from IO Magic (not great).

The games are Scrabble Complete (runs from the CD) and Trainmaster V4.2 (runs from the HD). Desktop is 1024x768 high color 75Hz. The O/S is Win 2k w/sp3.

It seems either the system has a limit of 256 or maybe a P/S issue, BUT all tests pass. Especially after 24 hours in the extended mode (I think that was what it was called).

Most boards lose stability with all their RAM slots populated.

What operating system are you using and with all of your ram in how many mb do you have installed?

2k w/ sp3

4 sticks of 128MB each. 2 are the same manufacture, the other 2 are different manufactures.

How about a P/S issue? Though I doubt it even though it is only a 250W w/ a PII 450. Since it is a older board and I REALLY don't like Wintel, I really don't want to invest in this box. The memory was left over from another upgrade.

I think it can be explained as this: the system is very unstable with your choice of RAM. Not only are all the RAM slots populated, but they're two different manufacturers, this also poses problems. It does fine in low load and high load situations, but nothing in between. Me coming to this conclusion is because it runs fine on constant-load memory tests, but on games, where the load shifts from high to low very frequently, it becomes unstable. This is my theory, and whether or not it in fact what is happening is beyond me.

I don't believe it's a PSU problem, mainly because the only PSU problem I've heard of are random resets. I myself had this problem when running all my components in my old case, minus the V9, 5 case fans etc. with a 250W.

Is that right ?????

I'm not disputing it, but if thats right, then it sucks...

Surely the Manafacturers would know of this problem??

Whats the point in selling a MOBO with 4 Memory slots when you can only use 3 ???

Remember that not only do you need the power available to the chips, but that your motherboard needs to be rated to supply the number of physical chips on the RAM sticks themselves. Motherboards are designed to supply a certain voltage to each stick of ram, up to a certain level depending on what you plug in. Less chips = less power.

About a motherboard losing stability from having all ram slots populated: That is the sign of extremely shoddy craftsmanship and poor design. A motherboard should be able to have all its ram slots filled with the maximum amount of memory supported on supported chips and should be just as stable as with a single chip. Any other case (not taking power issues and poor memory quality or incompatibilities into consideration) is a sign of bad manufacturing. I know that Intel won't let a motherboard be sold with their chipsets unless it passes some odd thousand hours of burnin to ensure stability. All of my primary machines have ALL of their ram slots filled with maximum supported memory, and all work exceedingly stable.

Heh... I KNOW it's a myth, or something that occurs only when you are buying bottom-barrel hardware, and even then it's iffy.

Back when space was king (around the time Abit was on top with the BH6 and the long-awaited BP6), manufacturers would sacrifice an entire memory bank to ensure absolute stability - Even though the chipset supported more then that. They would *not* release a board they knew could not use what it was sold as being able to support. False advertising, I'd say.

Heh...better start believing.

Check out the DIMM slots/stable field, the first column.

Anandtech - VIA KT333 Motherboard Roundup

May not be 'most' but definitely 'some'.

ABit seems to have this problem.

That is a myth or it is just something that occurs because of shoddy craftsmanship, which I doubt because several good brands are listed as being unstable with their slots filled. I'm wondering just what they define as unstable and how they come to this conclusion. I have never heard of this in all my years as a technician. I have known of companies to put less slots on a board than originally designed because of stability but that is mostly with industrial boards. It has been known to be the same in consumer products in the past.

I was having the exact same problem with an FIC board. I think it was something on the motherboard going bad because I also kept a hardware failure error message when I tried to install Win 2000.