Baoran wrote on 2023-07-22, 19:05:
CUV4X version seems to be working fine. I have a coppermine cpu running at 1.5V and hardware monitor shows the set voltage correctly too.
Interesting, thanks! The CUV4X BIOS is based on a relatively new build. Maybe ASUS had moved initialization of VCore to an earlier spot by then.
riplin wrote on 2023-07-25, 02:15:
I was running a memtest and suddenly the program started stuttering and I was hearing high pitched beeping from the speaker and the power led was flashing. This lasted less than a minute and then it stopped.
[...]
About those voltages, I'm using a brand new EVGA 100-W1-0500-KR 500 W1, 80+ White 500W, 3 Year Warranty, Power Supply 100-W1-0500-KR
I'm not sure what exactly might cause the beeping and stuttering, but if you want to make sure it's not the mod's fault, you could try again using the stock BIOS. It should work in your configuration (except for the non-critical hardware monitor error due to the missing -5 V rail).
A note on the voltages: Strictly speaking, the +5 V rail is out of spec according to the ATX standard (5 V +/- 5%, so no less than 4.75 V).
Usage of the rails (and thus the design of power supplies) has changed considerably since the days of early ATX systems: Back then, PCs got most of their power from the +3.3 V and +5 V rails, while today's PCs depend heavily on the +12 V rail(s). This means two things:
- While your power supply can nominally deliver 500 W, a Pentium III system cannot utilize most of this power. Instead, it draws almost excusively from the +3.3 V and +5 V rails, which are rated with a combined output of "only" 120 W. (The +12 V power basically only goes to the system's drives.)
- The PSU is loaded "the wrong way" (cross load): Since today's PSUs expect to be primarily loaded on the +12 V rails, some of them can develop problems if that is not the case.
I'm not saying that this is necessarily the problem here (and there are debates on how much of an issue this actually is unless you want to run a power-hungry Athlon system). Still, it is something to be aware of when choosing a PSU for a retro system. Should you have a different PSU at hand, you might want to try that one.