XMP profile setting very high voltages?

[clairvoux]

Greetings.
I have an Asus X99-S motherboard, 4x4GB 3200Mhz G.Skill TridentZ DDR4 memory and an i7 5820K.

Until today, for some reason my system would refuse to boot with XMP profile enabled, and manually setting RAM speed to anything above 2400Mhz would result in the system booting without detecting all 4 sticks of memory or not booting at all. Eventually I managed to get my system stable by manually setting the speed at 2666Mhz and with a small bump of 75mV on the system agent voltage.

Today after updating the BIOS to version 2101 on my X99-S board, I decided to enable XMP profile hoping for the worst, and to my surprise the system actually booted! It is the first time ever the system manages to boot with the XMP profile enabled.

So the XMP profile works now, but it bumps the system agent voltage to +358mV to achieve 3200Mhz. I honestly have no idea if that's safe or not, but to me it seems a bit extreme and it got me worried. If anyone could help me or give me some information about system agent voltages, it would be greatly apreciated.

CPU is not overclocked, all voltages are set on Auto and HWMonitor shows no voltage offset on anything other tan the System Agent Offset.
HWmonitor is reporting idle CPU temps of 20ºC and 44ºC under load on the hottest core running Asus Realbench. CPU package temp is reporting 62ºC for some reason, but I've read it isn't very accurate. However Aida64 is reporting 63ºC on the hottest core and 68º CPU package temp. That just makes things more confusing.

 

[Tradesman1]

Should be fine, the System Agent voltage (often listed as VCCSA) feeds the MC (memory controller) and gives it that extra boost....another approach is to OC the CPU slightly and then can often reduce the VCCSA voltage

 

[photonboy]

1) The package and individual core temperatures are often about 5degC apart. They aren't measuring the same part of the CPU so that's normal.

Throttling is somewhere around 100degC, but Intel likely lists about 75degC as the max "optimal" temperature for maximum life of the CPU. 68degC isn't a problem. I don't know if that's the correct value for you, but either way there's no need to get that cooler.

2) +358mV for the memory controller seems about right based on other info I've read so I wouldn't worry about that.

3) *I would suggest using Memtest86 www.memtest86.com
- may need to change BIOS boot order (or manually select boot device just to launch it from BIOS if possible)
- run the FREE version for a FULL PASS.
- Use the default configuration. Do note that some of the CPU configurations for using multiple cores in the test can result in FALSE POSITIVES (says errors when there aren't)

- also go to Intel and get the Intel CPU diagnostic tool and run that. It takes about two minutes or so and will just say "PASS" if it does.

 

[clairvoux]

Thanks for the quick answers!

Makes me feel better that it's not overvolting too much. Is there any offical number on a max safe voltage for System Agent? Also how does OCing the CPU makes the memory controller more stable, or require less voltage? I usually run mine at 4,4 Ghz, but since I updated the BIOS I haven't overclocked yet.

I ran memtest overnight last week, and thankfully no errors were found
I just ran Intel diagnostic tool, and it passed all the tests.

I tried manually reducing the system agent voltage to +250mV and it boots at 3200Mhz with no trouble and all 4 memory sticks detected. I'll keep lowering it manually to see if it can go any lower.

 

[clairvoux]

Update: I set VCCSA to stock (+0mV) and to my astonishment it booted all the way to windows with all 4 sticks and 3200Mhz!

That's weird. Before BIOS 2101 I had to set +75mV at 2600Mhz for it to boot correctly.
I just wished Asus released some sort of patch notes to let us know what was changed between BIOS versions...

 

[Tradesman1]

You never know what all is in a BIOS update, they normal will list one or two items, but there is almost always a lot more (especially updates for DRAM compatibility as new sticks are constantly coming out with a variety of timings and data rates.

 

[photonboy]

Update: I set VCCSA to stock (+0mV) and to my astonishment it booted all the way to windows with all 4 sticks and 3200Mhz!

That's weird. Before BIOS 2101 I had to set +75mV at 2600Mhz for it to boot correctly.
I just wished Asus released some sort of patch notes to let us know what was changed between BIOS versions...

that's good, but remember to run Memtest86 for a full pass to verify things are working