Prime 95 failure - advice needed

[wilsonian]

Hey peeps,

First off - system specs

CPU - AMD Phenom II X6 1055T
Motherboard - Asus M4A89GTD PRO
Memory - Corsair 2gb DDR3 X4 = 8gb

My system has been locking up intermittently for the past few days. I've ran a Memtest 86+ soak test which passed fine but when I ran a Prime95 test the 6th core failed within 10 minutes and after 20 minutes Prime95 crashed out.

Would people think it's the CPU or the Motherboard that has caused this failure? I know the system is old and I have plans to upgrade it however I'm hoping to salvage some parts for a 2nd PC that I can start using to learn Linux on. Thanks.

[watercooled]

First off, is everything at stock? Also, do you have any overclocking apps installed (including those provided on the motherboard's driver CD), or have any auto-overclock profiles set up in BIOS?

It's really quite unusual for a CPU to be unstable at completely stock settings unless it's e.g. already been damaged by excessive voltage.

[DDY]

If everything is running at stock, some sort of power supply failure springs to mind. Either the PSU itself or the motherboard's power supply circuitry, either of which due to some fault is unable to cope with heavy loads, ultimately causing instability issues.

Another suggestion is to update the motherboard BIOS, I spy on the ASUS website that there have been BIOS updates for the M4A89GTD PRO which [sic] "Improve syatem stability".

https://www.asus.com/Motherboards/M4...Desk_Download/

EDIT: Oh, and what PSU are you running?

[wilsonian]

Thanks for the quick replies. The System was a Scan OC bundle back in 2010 however around 3 years ago I updated the BIOS after I noticed the "Improve system stability" version - since then I lost all the OC settings (it removed the saved profiles and Scan never responded to a request for these) so have since ran it at stock settings. The PSU is a Lian Li but I can't remember which one - I think it's either a 650w or a 700+ version - I remember getting a high W rating but I'm currently at work so can't tell you the exact model.

Just a side note but the BIOS and windows 10 reports the CPU is running at 2.8ghz however when I loaded up 3D Mark it reported the CPU at 3.3ghz. I've disable any Asus auto OC functions and don't have any 3rd party OC software installed.

[DDY]

The X6 1055T has a stock frequency of 2.8GHz and boosts to 3.3GHz, it's plausible that Windows and 3DMark have reported the two respective values and I don't think this is an unusual occurrence.

I'm not familiar with the reputation of Lian Li power supplies or their OEMs, but at six years old I wouldn't be too surprised if the PSU doesn't run as well as it used to. Not to imply that I think PSUs don't last for more than six years, but considering the symptoms, swapping the PSU with a known good PSU is one of the first things I would try.

Another thing I'd try is to stress the CPU using Linux off a live USB (or CD) to determine if the issue is related to software or hardware.

[Ferral]

Daft one, have you cleaned fans and the fins on the CPU heatsink and maybe a new layer of thermal paste, also hoovered out any excess dust from case vents etc, crash could well be down to overheating

[wilsonian]

Yeah I like to think I take good care of the dust side - it gets cleaned out regularly and the dust traps cleared.

With regards to the PSU - I do have a new Corsair 450w unit I could try. I'll have to looking into the linux bootable CPU test.

[wilsonian]

OK so a little update. I've reseated all the power connectors and made sure it was completely dustless - been about 6 months since I'd last done it so it was fairly clean. I ran another Prime 95 round of tests and this time core 4 decided to fail after about 20 minutes but Prime95 didn't crash out like it had done a few days earlier. I had a little search and I've noticed comments on other forums that suggest Prime95 doesn't like the AMD Phenom and FX range. An odd suggestion but the comments recommended using the Intel Burn test. The system passed doing 30 loops of the standard test so I've increased this to the maximum setting and kicked it off again before I left for work. Fingers crossed...

[watercooled]

I'm not sure why those processors would have a problem with specific processors - in some cases very specific workloads can cause instability while others are fine as they stress different parts of the processor e.g. AVX requires higher voltage on some Intel processors, but you shouldn't just get application specific arithmetic errors unless something is fouled up in the software's CPU dispatcher for example; either way if a stress test is showing instability something is wrong. I don't have any of those problems on my own 1055T and nor do friends with FX processors so it's not a platform bug or something. I (like many others) have had things like y-cruncher running for days at a time on my CPU with no ill effects.