vdroop

[thepieces]

For me it helped a GREAT deal on my GA-P35 DS3L

Here's some data from my q9550 and GA-P35 DS3L 8.5x 400 3.4ghz , ram 2x 800ddr , FSB overvolt +.2 Ram +.1v

Stock: 1958 ohms bios voltage: 1.31875v
idle: 1.28v
load: 1.232v

Mod1: 990 ohms bios voltage: 1.31875v
idle: 1.28v
load: 1.26v

Mod2: 708ohms bios voltage: 1.28125v
idle: 1.264v
load: 1.248v

I had to lower voltage from 1.31, because it actually reported 1.31 ish in bios. Crunching prime 95 small fft's all night it is stable at 1.28125v. I had to get at 1.31875v before and stability was still questionable ! So whether penciling is hurting the board who knows. But i could not get anywhere near stable at these lower voltages.

Here is link to mod http://www.ocforums.com/showthread.php?t=558347

 

[yh125d]

Awesome. yet another necro thread. 1.5 years this time

 

[Idontcare]

Surprisingly though the contents of the thread are still relevant though, +1 for the necro poster for using the search instead of opening a new thread which would have then resulted in a rehashing of the topic's history.

 

[evolucion8]

My CPU at 3.82GHz, if I disable Load Line Calibration, I have to set the Vcore at 1.35V to be stable, and when I use Linpack or Prime95 to torture it, it drops at 1.24-1.25, but remains stable, with LLC enabled, it only drops from 1.26 to 1.24, but I'm a bit scare with the transient issue, so I just leave it there. I doubt that the CPU idles wasting lots of power at 1.35V.

 

[imported_Shaq]

Good try but I'm not buying it. lol So I should set the voltage in BIOS that allows the most fluctuation in voltage? On my board if I set the voltage in the BIOS at a certain amount I get a lot of fluctuation between idle and load, but if I set it 1 notch higher there is much less fluctuation in CPU-Z. So if it is measureable in CPU-Z it is probably even much higher than it shows. Is 0.1v "allowable" or is it a goal that should be strived for?

 

[superstition]

Perhaps the world's most massive "necro", but I find it interesting that nearly all motherboards aimed at overclocking now have LLC, usually with multiple levels and am still in the dark about why such a massive shift has occurred.

The original argument against the use of LLC was that it defies a basic principle of physics, right (trying to have one's cake and eat it, too)? But, apparently that has changed since Anandtech's original article condemning LLC was published. The argument was that, in order to reduce droop (which was supposed to be a good thing) big nasty overshoots are the consequence.

What changed? Is bad voodoo easily marketed or is LLC really an improvement? If it's the latter, has something about the design of the boards and/or chips changed to make it more favorable?

I have tried my hand at overclocking with three motherboards over the years:

1) DS3L — awful vdroop... I gave up on overclocking and decided to undervolt and underclock instead so I could run my Tuniq cooler passively for a music PC.

2) P55 UD4P — only one LLC setting. I struggled with instability with overclocks for years until I finally broke down and enabled the single LLC setting. Suddenly I didn't have problems with stability and my overclocks were just limited by heat. I was able to settle at 3.75 or something with my H50 and Lynnfield i5 at a reasonable volume level.

3) 970A UD3P with 8320E. For this board I have found that the medium setting works the best to reducing droop the most and enabling me to use a lower voltage setting in BIOS. It also seems to do a decent job at preventing high spikes. I tried other settings but went for medium initially due to this article which has a chart that showed that setting doing the best job with a different Gigabyte motherboard and a 9590.

It's my impression that LLC of any kind does increase at least the amount of heat put out by the VRMs and possibly the chip as well. However, it also seems to make it a lot easier to get a stable overclock. I thought I was the world's most incompetent overclocker until I finally turned on LLC with the P55 board. I had not done that because it only has one level, probably an "extreme" one and I had read at least one comment in a forum that said it's too harsh a setting. But, it was definitely a pleasant experience to finally have easy overclocking stability.

So, if you all can get over the age of this topic, I would love to know why the change has occurred. Is LCC now viable because there are less extreme levels? That doesn't seem like the answer, though, because people were doing different levels even with pencil mods. So, I assume there is some sort of hardware or BIOS code that makes LCC more compatible with boards — making it less prone to causing nasty overshoot.

This is my first forum post since 2008 or so, by the way.

 

[DrMrLordX]

Wow, double necro. Can we go for a triple?

LLC seems ubiquitous these days. I still don't much care for anything over 20%. It seems that, in some circumstances, you limit your overall clockspeed ceiling if you rely too much on LLC for stability @ 100% load.

 

[superstition]

Wow, double necro. Can we go for a triple?

LLC seems ubiquitous these days. I still don't much care for anything over 20%. It seems that, in some circumstances, you limit your overall clockspeed ceiling if you rely too much on LLC for stability @ 100% load.

What do you think of that article I linked to? It definitely looks to me like the medium setting is a lot better than the others, and a lot better than having it off.

Is this because it doesn't show the nasty overshoots or has that issue been dealt with?

P.S. It is a triple because I haven't posted here since 2008. I don't like unsolved mysteries, though, and I noticed the topic when looking at my posting history. I've been meaning to revisit this for some time.

 

[DrMrLordX]

What I've noticed is that not every processor/board combo really likes LLC that much. Some boards do unexpected (read: stupid) things with LLC settings. Some processors like relatively stable voltage more than they like wild swings up and down as load increases/decreases.

Sometimes doing things the "old fashioned way" is generally better, even if that leads to unnecessarily high voltage at low/no load. Medium (usually 20%) LLC is just a nice way of pushing back against vdroop.

I will say that the article you linked saying that the Extreme setting wouldn't boot is pretty typical. Anyone who relies on settings like that is asking to be clock-limited, depending on the processor and board.

 

[2is]

I've read (though I'm not sure how accurate this is) that newer boards with more robust and modern power delivery are able to respond much quicker to load changes than older designs, so those overshoots when load decreases, while not completely eliminated are greatly reduced. Sounds plausible, but again, not really sure how accurate that claim is.

My board has multiple levels of LLC and I don't like using anything more than the lowest level (one step above none basically) My current OC is fairly light at 4.2GHz and don't need any LLC to achieve that. I can get another 200 or so MHz by increasing LLC up one notch but don't really see the need.