Just received my Intel Core 2 Duo E8400 retail chip

I know it's been posted, but vDroop is a good thing for more than one reason. If you need more volts, don't try to circumvent vDroop to get it. Continue bumping vCore until you're stable, or you're at a point that you don't want to go further...

I'll sign up for this

Looks like its time for a new CPU I love me E6400 but I want more onboard cache, and more speed can't hurt either.

If I get 1-1.3Ghz OC at say 1.35-1.4V I'll be more than happy.

Think I going to have to order this afternoon hopefully I'll get it on Friday

You're damn-near guaranteed a 1Ghz overclock on a decent chipset; looks like nearly the majority of people with good cooling are getting even further.

Albuquerque said:

I know it's been posted, but vDroop is a good thing for more than one reason. If you need more volts, don't try to circumvent vDroop to get it. Continue bumping vCore until you're stable, or you're at a point that you don't want to go further...

Click to expand...

I've read the article and threads about vdroop being a good thing and personally the arguments didn't convince me. They didn't measure the voltage spikes inside the CPU. I think there is circuitry in place to reduce or eliminate the spikes before they get to the critical components. I don't know this for a fact, but it doesn't seem like it would be hard to implement, and I don't know why high-end Mobos wouldn't already have this feature to allow for more stable OCs. Intel may very well have circuitry inside the chip package to help eliminate the spikes, and provide a cleaner signal.

Also, the current crop of 8800 gfx cards actually increase voltage under load to improve stability under load (when you need it most). I know that CPUs and GPUs aren't the same thing, but I still think the information can be interpreted similarly.

This is just my opinion based on my knowledge of electronics and what I've read. If you have any good info to the contrary I'm all ears, and would appreciate any enlightenment.

Mine's on it's way...

jason4207 said:

I've read the article and threads about vdroop being a good thing and personally the arguments didn't convince me. They didn't measure the voltage spikes inside the CPU. I think there is circuitry in place to reduce or eliminate the spikes before they get to the critical components. I don't know this for a fact, but it doesn't seem like it would be hard to implement, and I don't know why high-end Mobos wouldn't already have this feature to allow for more stable OCs. Intel may very well have circuitry inside the chip package to help eliminate the spikes, and provide a cleaner signal.

Click to expand...

AnandTech tested exactly what you are asking about, and there are very bad spikes that occur, and they occur for far longer than without the vDroop issue.

It is wise to leave it be

OnDborder said:

Mine's on it's way...

Click to expand...

Aye just finished ordering mine a few min ago

Definatly should be here by the weekend. Mwahahah.

ghost_recon88 said:

This is really scarry
1.) I can set the vcore in my BIOS to 1.505, then restart
2.) Check PC Health in the BIOS and it shows the chip as getting 1.4, boot into Windows
3.) Open up CPU-Z, shows 1.405 actual volts (lines up with PC Health)
4.) Put a full load on the CPU by running Prime95 and the CPU-Z shows 1.36 actual volts due to the vdroop.

This board is killing me Good thing an IC caught on fire the other night, so I can RMA it. BTW, those voltages were funny before the IC toasted.

Click to expand...

I think the Voltage issue is RMA worthy anyway. FWIW, My IP35-E pumps 1.560Vcore at idle when 1.565v is set in BIOS. (See SS here.) Under load it drooped to 1.52v (sorry, no SS for that). This is on an E4400 of course, but I'd expect results to be at least similar, not a .14v undervolt + vdroop; that seems extreme.

Albuquerque said:

AnandTech tested exactly what you are asking about, and there are very bad spikes that occur, and they occur for far longer than without the vDroop issue.

It is wise to leave it be

Click to expand...

That is the article I read as well. Anandtech is not the end-all-be-all of information. I realize the spikes occur, and that they measured them, but where were they reading the voltage? I seriously doubt that they opened the die, and were measuring the spikes as they traveled through the 65nm components. All it would take is some simple circuitry to eliminate the spikes. PSU's do this all day long. It is possible that the circuitry that eliminates or reduces the spikes exists between the measure points that Anandtech used and the 65nm components, and I think that is the major flaw w/ their argument.

I will keep my Voltage Damper option enabled, and I'm not going to return my gfx card b/c it has negative Vdroop, claiming that it is killing my GPU.

Edit: Just tried a little experiment. I have my BIOS setting at 1.5125v. With Voltage Damper enabled I get 1.488v idle, and it jumps between 1.488v and 1.496v under P95 load. This has previously been tested to be stable all night. I disabled Voltage Damper, and now I'm reading 1.464v idle, and 1.416v under P95 load. The only problem is 1 core fails in less than a second, and a 2nd core fails w/n 15 seconds. It's a little interesting to note that vcore goes up a bit w/ each respective core failure. It jumped to 1.424v, and then 1.432v.

I'm not sure what you're suggesting: those voltages were measured at the VRM output stage, that's what's going directly into the chip. No amount of measuring "on the die" will be different, because the only reason it will change "on the die" is due to the resistance (and capacitance) of all the little tiny transistors onboard.

Intel has very definitive and absolute specs for proper power regulation hardware; they do this because they depend on that hardware to feed their chips properly. There is no further regulation circuitry within the die itself; the electronics "on the die" simply aren't big enough to regulate that kind of power anyway. If the chip itself had the hardware to do what you're suggesting, then motherboard manufacturers wouldn't need to spend the money for six- and eight- phase power regulation.

The chip runs on what you send it, that's the bottom line directly from Intel. So if you're sending it garbage, that's what it's consuming. Your PSU (and even the VRM's on your motherboard) dampen these spikes by way of very large capacitors, and those capacitors begin to bulge and leak if they've been abused by too much ripple current. But at the micron-size level, there isn't enough capacitance in the entire CPU to regulate those kinds of power rippes and spikes.

I also have an E8400 on the way

I'm building a complete new system, all new hardware. I wanted to wait for the new quads, but i had to get one of these monsters!

I'll be perfectly happy at 4GHz! You guys have some impressive OC's, that's for sure

Thanks for the informative response.

There is a large cluster of SMC's on the bottom of the chip package. I wonder if these might help regulate the spikes. Of course the better the power coming in is always a plus, hence the need/want for 6 or 8 phase power regulation on the MoBo.

You make some valid points, and ultimately you may be correct. My testing doesn't involve using oscilloscopes, but in my experience turning the Voltage Damper option 'On' only helps to give me more stability.

You have encouraged me to do some more testing, though, so this all might turn out to be a good thing after all. I'm going to turn VD off and see how high I have to crank the Vcore BIOS setting to get stable again. I'll only be able to use temps and CPU-Z's Vcore reading as a power consumption measure, but I should be able to come to some kind of meaningful conclusion.

Thanks again for your knowledge and here's one on me!



Edit: And sorry for high-jacking!

the SMC's can help with the spikes as saying if they were being charged with a 1.4volts. then when it droped/drooped the cpu wouldnt see it since the caps have a 1.4volt charge. as the cpu voltage readsing are between the VRM to the CPU, so its somewhere in between the path. the best way to see the voltage would to get readings from the socket. you would need to find the corresponding pins and then use alligator clips, reall small ones to use on the back of the motherboard.. that would give you a closer or more real cpu voltage reading...

Well guys 4.3ghz wasn't stable so I've backed it down to 4.25ghz 500x8.5 with 1.45v measured at the coils with a DMM, this board has a .01v drop under load but it does not fluctuate. So setting 1.46v in bios gives me 1.45v under load rock stable.


By mysterfix at 2008-01-22

Hmm, appears a lot of people are hitting 4.2-4.3GHz Prime stable with 1.45 volts, myself included. That appears to be the sweet spot with these chips.

my 8400 will be here tommorrow, expect phase+8400 thread tommorrow

Don't forget to post your codes here too, I've had mine sitting here since Saturday waiting for my other stuff to get here (got this one from Microcenter), so it's nice to see what other people are getting w/ similar chips to mine

btw, my batch is Q745A356 and pack date is 12/27/07

Gregory_WE said:

Don't forget to post your codes here too, I've had mine sitting here since Saturday waiting for my other stuff to get here (got this one from Microcenter), so it's nice to see what other people are getting w/ similar chips to mine

btw, my batch is Q745A356 and pack date is 12/27/07

Click to expand...

Yea, I think we need to start a "45nm overclocking results" thread, where we put down CPU model, batch #, max stable overlock, voltage required, motherboard (and BIOS), and cooling used.

I just placed an order for one myself & should get it on Friday. Hopefully I'll be able to obtain a higher O/C then on my E6600 which for some reason I can only get to 3 ghz. If it goes the same I should be able to get 3.6 ghz, but aiming for 3.8 to 4 ghz

Just for a laugh, did anybody try a overclock on the stock fan & if so what was the results ?

man i just read all 8 pages. I WANT ONE!