Vdroop and the 990FXA-UD7

[mxthunder]

I have been doing extensive research on this motherboard (want to see one in my 700D real soon)
but have been reading about all the "issues" with Vdroop.

If you look here, and read post #85, they claim the mobo operates normally.

http://forum.giga-byte.co.uk/index.php/topic,5939.75.html

you can read about the issues in this thread:

http://www.overclock.net/amd-motherboards/1023100-official-gigabyte-ga-990fxa-series-owners-10.html


bottom line, should the motherboards voltage be dropping under load? I know what this can do to a stable overclock and question how well this mobo will work for me, especially since there is no LLC options in the bios.
Is gigabyte just trying to cover its ***?

 

[stevenb]

on Intel its supposed to drop under load.

btw I showed that thread to GB, and well they weren't totally aware. They were very interested when I showed them the thread at OCN. So if it wasn't under advisement, or it didn't go high enough, it just did last night.

 

[RGone]

I have been doing extensive research on this motherboard (want to see one in my 700D real soon)
but have been reading about all the "issues" with Vdroop.

1. Thru the threads, many are using workarounds and faring pretty good it seems.

2. If the Vdroop is a bother to you, then I certainly would n0t buy such board until the issue is fixed.

3. With as many as are blogging about what they feel is a problem, it should be easy enough to "know" when the issue is fixed.

4. Until then, knowing human nature, I certainly would not spend for a board that in a human's mind would always be suspicious to me...even after I bought it.

5. Beyond that there are new specs out of the "true" AM3+ cpus and those cpus are not currently in use by most on that later board. Things may certainly look different when a real AM3+ cpu is installed.

 

[Dolk]

Vdroop is always there under load. To fix it, use LLC. I don't know what options there are on the Gigabyte board that helps with LLC, but there should be some sort of variable tollerance for it.

 

[stevenb]

there was no LLC settings available to users, and the droop might be part of teh fact that board is designed for BD.

 

[mxthunder]

Stevenb, do you work for gigabyte or are you the one that goes by Sin0822 on ocn?

Do you guys think that .08V of droop is excessive?

 

[stevenb]

yea i go by sin0822, and no i dont work for them.

on Intel no its not, but its managable. on AMD i am guessing it is, but in the end i heard that its not as bad as that. its more like you set a voltage and it idles .04v over what you set and loads down to .03v less than what you set. You guys shouldn't be scared of a 40mv high idle voltage at any voltage, as the power consumption isn't going to increase, as it will under load when voltage is increased.

But i told GB about this problem, and i was told it will be dealt with.

 

[trents]

Vdrop and Vdroop are normal, for the same reason your house lights might dim a little when your electric furnace kicks in. Some motherboards have built in compensation for Vdrop and Vdroop, some have manual adjustments for them in bios called "Load Line Calibration" or LLC, some boards have both built in and manual and some boards have neither. Doesn't really matter how you compensate for the voltage fall off as long as you do it somehow, even if it means just jacking the main CPU voltage setting in bios higher without any LLC.

 

[stevenb]

vdroop mod is available, PM me.

 

[stevenb]

pleasedelte

 

[mxthunder]

Got my motherboard installed on Friday night. Vdroop goes from 1.425 set in BIOS to 1.455 at idle, then all the way down to 1.344 under load. Its gonna be a little tricky to get my CPU stable me thinks..

 

[trents]

Does it have LLC (Load Line Calibration) to compensate?

By the way, your board has negative vdrop and positive vdroop.

 

[mxthunder]

No options for LLC in the bios. Only CPU PLL voltage, etc. I may have to play with that.

 

[Woomack]

I haven't noticed so big vdrop on my UD5 and Phenom II 560. Setting 1.45V in bios I get about ~1.48V idle and ~1.42V while running F@H or Prime95.
Other thing is that I can't make my cpu stable after unlocking cores and I saw some other users complaining that their cpus were unlocking without problem on other boards but on 990FXA-UD5/7 are unstable. I will change cpu in some time but I'm just curious if any bios can fix it.

 

[mxthunder]

I have heard that the less wattage the cpu draws, the lesser the v droop. People with quads and hex's are shutting down 2-4 cores and seeing less vdroop on load. Makes me think its a weak power phase system, as opposed to what gigabyte claims.

I cant get tri SLI to work either. Lots of early adopter bugs with this board.

 

[stevenb]

do you know how to use a soldering iron? its a pretty easy mod man:
I take no responsibility for what you do.

GB's official response was what i stated it to be, that its part of AM3+ design, if you try and look for the PWM used, and the PWm controls the droop, its still under NDA. its new tech man.

990FXA-UD7:

PS: the UD5 has a very similar vdroop mod possible too, but I need an upclose picture of its PWM, just like the one above.

 

[hokiealumnus]

Bumpity bump! Looks like I might need to hard-mod this thing if I ever plan on taking it cold. I'm amazed that such a high-end board has no LLC control. Consider this a chink in its otherwise strong armor for the review. 1.45 Vcore in BIOS, 1.472 idle / 1.360 1.344 load in Windows.

 

[hokiealumnus]

Pardon the lazy man's watermarking (using the background) in the images below.

Here I show idle & load in windows. The set Vcore is 1.5V, out of necessity because anything below that causes instability under load.

So first, we have loaded voltage while running LinX to test for stability. 1.392, exactly where there Cross V was for this overclock. All is well here.



....then the test finishes and you see what I was astounded with before starting it.



Yep, you read that right - 1.52V!

0.128Vdroop. Horrible for a board of this calibre, at least without the ability to compensate with LLC. The ASUS board was not quite that bad with LLC turned off, but it has such fine-grained control that idle voltage pretty much = loaded voltage. As it is, I wouldn't want my CPU seeing 1.52Vcore 24/7.

So, barring some BIOS improvement, Gigabyte voltage regulation is a fail so far. You can bet I'll be contacting them before writing the review though, so if there is anything other than a hard mod to fix this, I'll dig it up.

 

[stevenb]

yea man good luck.

BTW if you do that mod, i did it. what you are seeing for vdroop will be vrise lol.

 

[mxthunder]

Thanks hokie, let us know what you find out!