FX 8350 - Inaccurate Core Temperature

madcratebuilder said:

I've run the 80i with a 8350@4.6ghz, normal everyday work fans run under 1200 rpm, when you stress test they go up to max and are loud but only when pushing the system to the max.

I tried a few different rad arrangements on the back of the case. Rad mounted inside in push/pull, rad mounted outside in push/pull, temps within margin of error. I settled for rad and push fan inside case and the pull fan on the outside. That gave me a little more room inside for air circulation around my xfired gpu's.

I hear you about stuffing gear inside the case, I'm about half done with the wiring.


It's a little cleaner on the other side.

Very nice rig , stupid question of the day, what is the purpose of the 2 small fans to the rear of the CPU socket?

Nice looking rig Madcratebuilder, good job mate

@Indianatone, The Crosshair v Formula can get a pretty toastie Northbridge when overclocking so I'd imagine those fan's are too help cool that. I know of people that hit cpu oc's of 7Ghz + on that board with North bridge temps of 100c without additional cooling for the north bridge without issue though.

Nice rig, madcratebuilder.

MagusMagnus said:

Bingo.

The main problem with the M5A97 R2.0 paired with the FX-8320/50 rests with the fact that that board only has a 4+2 VRM (voltage regulator module) power phase whereas the M5A97 Evo R2.0 has a VRM 6+2 power phase and also the M5A99FX Evo/Pro R2.0 has a 6+2+2 VRM power phase.

The VRM is responsible for dampening down the 12V supplied by the PSU and is therefore in turn actually feeding the CPU its-converted-voltage directly... it literally keeps the CPU from frying. Essentially the rule of thumb is the more powerful the CPU the more VRM power phases are necessary to adequately feed the CPU the proper voltage, being neither too much nor too little. Ideally, these chips wouldn’t be paired with any board with less than an 8 VRM power phase (which would include the three aforementioned because technically, they are at 6+2 and 6+2+2 respectively).

In other words, that board (actually all 4+2 VRM power phase boards in general) simply was not designed with the FX 8-core chips in mind, the 4+2 VRM power phase boards really shouldn’t be paired with anything more than an FX 6-core and that in fact is the FX series available at the time of their design and release in the first place.

Asus should never have revised this to be “compatible” with the FX 8-cores because it really isn’t, not in its actual, physical design. The only reason it ‘works’ is the technicality of fact that it is still AM3+ socket but that is truly where the “compatibility” ends here. That boards VRM is just not good enough for that chip at stock, let alone compounding the problem further with overclocking. Yikes.

Thanks for the good information. I came to the conclusion that my motherboard wasn't up to it and I ended my quest at overclocking a while ago. At least until I can get a better motherboard. Something like a Sabertooth if it's in my wife's budget. lol.

I know necrophilism has become a hot topic of debate these days (pun intended), but if i may just add some of my findings in here - as i was searching for a friend of mine as he got also heat-issues using the FX-8320 …

Solarstarshines said:

I think it's the mobo because the 970 and 980 are two generations back and i notice when people use a older board for a FX chip the voltages are just way higher

MagusMagnus said:

[…]
The main problem with the M5A97 R2.0 paired with the FX-8320/50 rests with the fact that that board only has a 4+2 VRM (voltage regulator module) power phase whereas the M5A97 Evo R2.0 has a VRM 6+2 power phase and also the M5A99FX Evo/Pro R2.0 has a 6+2+2 VRM power phase.
[…]
Ideally, these chips wouldn’t be paired with any board with less than an 8 VRM power phase […].

In other words, that board (actually all 4+2 VRM power phase boards in general) simply was not designed with the FX 8-core chips in mind, the 4+2 VRM power phase boards really shouldn’t be paired with anything more than an FX 6-core and that in fact is the FX series available at the time of their design and release in the first place.

Asus should never have revised this to be “compatible” with the FX 8-cores because it really isn’t, not in its actual, physical design. The only reason it ‘works’ is the technicality of fact that it is still AM3+ socket but that is truly where the “compatibility” ends here. That boards VRM is just not good enough for that chip at stock, let alone compounding the problem further with overclocking. Yikes.

I just wanna drop in that a FX-8350 without any difficulty can be used on boards which may only featuring a 4+2 VRM power phase design. This isn't to proof anyone wrong but to confirm that the board‘s manufacturer ain't that wrong as they releases or flag given boards to be compatible with the highest Bulldozer‘s FX-8xxx series.

As far as i'm concerned and where the message comes in here … I bought a rig a few years ago, custom build which featured the following parts:

• CPU: AMD FX-8350
• CPU-Cooler: be quiet! Dark Rock Advanced C1
• MB: AsRock 970 Extreme3 R2.0
• Mem: Crucial Ballistix Tactical, 16 GByte, 1866 MHz, CL9
• GPU: AMD Radeon HD 7850 Black Edition, 2 GByte GDDR5
• PSU: be quiet! Straight Power E9 580W-CM
• Case: CoolerMaster HAF 912+

The 970 Extreme3 R2.0 has only a 4+1 VRM design. But despite lacking any good VRM design (read: ±4+2 phases) i never ever ran into any trouble at all. No throttling, no drop-out or something similar.

Remarkably though, the whole system stayed and stays pretty cool - barely reaching any temperatures above 55°C (package or core) even under heavy load (Prime 24hrs). The GPU idling down at 23°-25 or 27°-29°C (depending on ambient temperature) reaching a maximum at ~45°C under heavy load with games/applications and ~50°C on FurMark (24hrs).

I was quite surprised and set my bet on false read-outs as i even bought some infrared thermometers (Voltcraft IR-2200-50D & FLUKE 62 MAX+, Infrared Pyrometers) and tried every monitoring software around - knew about AMD‘s changed measuring scheme though - to just be eventually proven wrong.

The system in fact is just amazing cool!
It turned out that the VRM reaching ~25°-30° C when idling and come close to 45° C under load.
I guess it's just a nearly perfect mix of the heavy weight CPU-cooler, the really nice case (it isn't branded as HAF; → reads „High Air Flow“ for no reason …) and the quality PSU which ensures some reliability.
It's even capable to boost given cores via Turbo-Core™

For storage my own rig got some 500GB, 1.5TB & 2TB HDD and a 256GB SSD i used before.
The whole system taxed 750,50 € back then including the 2TB HDD and a Cherry™ CyMotion Expert Combo beyboard.

As a matter of fact i bought this identical setup seven times to date, to configure and assemble it for other guys around - as some came by and kept wondering how surprisingly cool and freaking quite it run. No-one ever complained about anything and all of them are still in service - some where upgraded with better GPUs over time but didn't struggle to maintain silence and temperature after all. Mine got a R 290X a while ago too. Just one of them had serious heat-issues and therefore throttling as he tenaciously insisted to use his own case and CPU-fan he salvaged from an older rig.

So, a minor amount of phases on a VRM design doesn't necessarily mean it couldn't fire a high-performance setup …


In this sense

Smartcom