[hiemal]

Okay, so updating the first post...

Yes, overclocking your ES skylake is 100% possible. You can do it even without the non-k bios (at least, with the Asus z170-k I was using!).

Keep in mind, though, depending on the model you use (the QHQG is the one I'm using) has a low multiplier that would require a BLCK over 170 to reach stock i7-6700 speeds.

Most motherboards using the standard clockgen cannot handle this. Your board will have severe stability issues, and will crash a lot if you can get your board to start at all. More voltage to the core, or to the PLL can fix this to an extent but you WILL reach a wall where you'll get such huge diminishing gains it's impossible to get any farther. You'll need to get a Z170 motherboard with a dedicated clockgen.

So to recap.

OCing is possible. You don't lose AVX instructions, temps read out ok and I'm pretty sure the integrated GPU still operates fine. Turbo boost also works, as well as speedstep. So, basically every issue with normal non-k OCing you shouldn't have, which is obviously a huge bonus.

Now, I'm also going to say this was MY experience with this. I do not know if this will apply to all ES CPU's, or to all motherboards, so take these results with a grain of salt. If you can get it to work, you can get a really nice CPU for considerably cheaper than normal price.

 

[hiemal]

Anyone have an answer?

 

[GreedyMuffin]

The 6400 is a quad-core?

four cores/four thread making it a I5 (as it is) and not a I7?

 

[hiemal]

It's an engineering sample so it doesn't have the actual name of the chip on it. The seller has it listed as an i5-6400T, (which is incorrect) but from the info CPU-Z has given its actually an i7 engineering sample. Shows 4 cores, yes, but it has 8 threads.

 

[GreedyMuffin]

Ahh!

Awesome!

 

[xGeNeSisx]

Quote:

Originally Posted by hiemal

It's an engineering sample so it doesn't have the actual name of the chip on it. The seller has it listed as an i5-6400T, (which is incorrect) but from the info CPU-Z has given its actually an i7 engineering sample. Shows 4 cores, yes, but it has 8 threads.

Very strange about the ES edition, I can't provide any input on that. I have an i5 6400 which has a 2.7ghz clock default and up to 3.3ghz turbo. I have achieved stable BCLK overclock using an ASRock Z170 K4 of up to 4.8ghz easily. I am currently running at 4.4ghz for daily gaming/usage with a Vcore of 1.32.

I have heard many say that they have to compromise the amount of DDR4 frequency in order to achieve stability, as it is tied to BCLK. Most guides advise not to exceed 2600mhz due to instability. I have not found this to be true in my case, I can run 2x 8gb G.skill sticks at 3000mhz at 14-15-15-35 timings (still messing around with them). There is vast overclocking potential if you have the right board and BIOS for it in my opinion.

 

[hiemal]

I did more snooping around on this CPU and apparently it's dubbed a code i7-6400T. Obviously a weird part number but it fits with what it sounds like. Another person actually found this CPU too and was asking questions about it on Reddit so.

I'm also thinking this is a later revision since it has the Intel logo on the IHS and looks more refined than the ones i've seen on Google.

But again, who knows. All speculation. I ordered a motherboard and some RAM so we'll see how it performs in a few days!!

 

[The Pook]

Some people run into issues with BLCK speeds above 160-175 or so. With a budget Asus Z170-E and i5 6400 I can run 170 BLCK for a few Pi runs, 165 for games but have to lower it to 162 to pass stress tests. 1.285v @ 4.37ghz is my 24/7

definitely a cool sounding chip though. CPU-Z screens when you get a chance or voteban

 

[hiemal]

I guess the seller has more if anyone else is interested.

http://www.ebay.com/itm/ES-Intel-Core-i5-6400T-2-2-2-6GHz-Quad-Core-65W-Skylake-CPU-Processor-LGA-1151-/182125943447?hash=item2a678d5a97:g:ekMAAOSwoudW6Fed

 

[unclewebb]

Just for the record, Intel ES CPUs are owned by Intel. Buying one on EBay is the equivalent of buying stolen property.

This CPU sells for 750 Yuan in China which is equivalent to $115 US so someone is making a decent profit selling stolen property. Here is the CPU-Z screenshot from the EBay seller's post.



http://i.imgur.com/NaROb6z.png

This CPU has nothing to do with a Core i5-6400T. It is a Stepping 1 which means it is an initial ES processor. The retail Skylake CPUs are Stepping 3 so Intel likely fixed quite a few bugs between the initial ES and the retail version. All CPUs, including retail CPUs, have a long list of mostly minor bugs. For a gaming rig, you will probably not have any problems.

The good news is that this CPU is likely an early test version of the Core i7-6700, non-K. The multiplier is limited but other than that, it has more in common with this Core i7 compared to any other Intel Skylake CPU. It has the locked max multiplier, 8 MB of L3 cache, 4 Cores, 8 Threads and the all important 65 Watt TDP. The i5-6400T is a 35 W part without hyper threading so it is completely different.

http://www.silentpcreview.com/Intel_Core_i7-6700

When BCLK overclocking, you will lose the AVX instructions which kills performance in some benchmarks and in some professional software but for many games, AVX doesn't make much of a difference. Post some pics when you get yours up and running. On a good board, you might get a decent overclock out of it.

 

[BertoM]

You seem pretty knowledgeable regarding the engineering sample CPUs so if you wouldn't mind I would like to ask a few questions.

The base clock is 2.2Ghz with boost to 2.6Ghz, should you be able to set 26 as the max multiplier?

Do you see any reason you wouldn't be able to BLCK overclock these ES CPUs?

I ask because being limited to a x22 multiplier means that a base clock of over 180 would be required just to reach 4Ghz. I BCLK overclocked an i5 6400 and it was stable at 4.4Ghz (163 or 164 base clock I can't remember) at only ~1.25V, but bumping up the multiplier by just 1 caused issues no matter the voltage (boot but with no monitor output, wasn't boot looping). I am guessing this was likely due to my motherboard not having an additional clock gen like manty Z170 boards do (I was using a MSI Z170A PC MATE).

 

[unclewebb]

The max 26 multiplier is likely only available when running the default 100 MHz BCLK and it might only be available when a single core is active. On locked CPUs, as more cores become active, the multiplier usually drops. When BCLK overclocking, you are stuck with the 22 multiplier and you will need to use a board that likes to run at a very high BCLK to get the most out of your chip.

Some Asus Z170 boards have a feature called Pro Clock Technology which allows them to run at sky high BCLK values.
Quote:

Meet ASUS Pro Clock, a dedicated base-clock (BCLK) generator designed for 6th-generation Intel® processors that ramps BCLK frequencies up to 400MHz or even beyond*.

This feature is available on their high end boards but there are some boards like the Z170-E that also use Asus Pro Clock at a reasonable price.

http://www.newegg.com/Product/Product.aspx?Item=N82E16813132691&cm_re=z170-e-_-13-132-691-_-Product

Here is a list of Asus boards that shows which boards have this feature.

http://www.asus.com/us/site/motherboards/Z170/compare/

Other manufacturers might have a similar feature.

 

[hiemal]

Well shoot. I bought a used z170-k, which doesn't have that feature. I guess I should probably resell it back out and get one with the pro clock thing.

 

[JackCY]

ES, engineering sample, which means what ever Intel enabled on that CPU will be enabled and there is no way for anyone to find out, you just gotta test it yourself what works and what doesn't. I don't know if Intel owns ES sample CPUs but obviously someone got their hands on them and is selling them, maybe if Intel wasn't so greedy and wasn't locking BCLK OC out of everything but K series people wouldn't consider so much to buy cheaper ES random samples on ebay.
The BCLK OC on Skylake has been disabled by microcode, mobo manufacturers also updated their newer UEFI versions that removed the BCLK OC for nonK, Intel stomped on it as usual when people started buying cheapest i5 and i7 instead of overpriced 6600K and 6700K while achieving similar OC. Too bad you can't just enable HT on i5s etc. by using a pencil, such tricks were possible many years ago to unlock CPU features. Intel wants people to buy K series if they want to OC, pay the hefty price for it and disable it for everyone else so they can keep the money going until AMD comes up with something better to challenge them.

 

[BertoM]

BCLK overclocking is pretty much in the exact same state as it was when it was first released. With the correct bios, you can BCLK OC to your heart's desire. MSI has even released an updated BIOS:

http://overclocking.guide/updated-msi-z170-non-k-overclocking-guide-new-bios/

 

[BertoM]

Quote:

Originally Posted by hiemal

Well shoot. I bought a used z170-k, which doesn't have that feature. I guess I should probably resell it back out and get one with the pro clock thing.

Without an external clock gen 170 is the highest you can set the base clock, so ~3.7Ghz max with a 22 multiplier.

I would wait to get the board and chip to ensure that BCLK overclocking works on the eng sample chip before investing more into another mobo.

 

[hiemal]

...so this is odd
I got the chip motherboard and all that set up today. Started to test things.... Got the clock up to 150 mhz.

What's weird though.... Is that the BIOS version is from 10/26/2015... Which I'm pretty sure is before they released the whole non k overclock.

BIOS also reports that turbo still operates fine, along with accurate temperatures.

I'll do more extensive testing tonight when I get home from work. Gonna get Windows running and do some benchmarks and whatnot. Pretty excited!!!

 

[unclewebb]

The Ebay seller has dropped his price 10% so if your numbers look good, he might have some buyers lining up.

It will be interesting to see if Turbo Boost still works in Windows when you have the BCLK at 150 MHz. Looking forward to your tests.

The benchmark in XTU should confirm if the AVX instructions are working or not.

 

[Tcoppock]

I have this cpu+asrock z170 pro4s, can in fact say that the low end boards like ours will not get much further than 172.8 stable.
I have tried it on a different motherboard and got over 190 but it wasn't mine. Will be looking into purchasing a better board at a later date still want to pick up a second gtx 980 first.

 

[hiemal]

this is what i'll leave with for the night.

I haven't had a chance to really play around with any values yet, but turbo boost does in fact seem to work. The frequency also changes dynamically, so speedstep is still working. Temperature readings however are not, and is stuck at 100 C as expected.

I can't seem to get intel XTU to actually start though, I wonder if it's having issues since it's an ES processor. Throttlestop also won't work, says it's an unsupported CPU. Guess OCing will have to be solely on the bios then, unless there's some other program I'm unaware of that could potentially work.