Skylake is here!

[TechguyMaxC 516]

What about RAM frequency. Do you think it's worth pushing the boat out with Skylake and opting for high frequency, or low latency as the priority?

 

Hasse will have more direct information than I, my only DDR4 experience was with Haswell-E 5960x and that chip could only do 4.4-4.5GHz so it was slower than the 4770k @ 4.9GHz which it replaced.  In theory though, there has to be a balance between throughput and latency to get the best performance in every scenario, and that is the key.  You can blow away a single benchmark record by focusing on one aspect of memory performance but you won't have good performance all around without finding that "sweet spot".  Note: when I say sweet spot in this case I am not referring to the price.  Hasse said that with DDR4 this sweet spot is a good deal higher than 3000MHz and with CL around 15.  I'm inclined to believe since I don't recall my 5960x with 3000MHz CL15 DDR4 being any faster than my 4770k with 2667MHz CL11 DDR3.  As I mentioned, there was a 400-500MHz clockspeed deficit on the 5960x system though so without super fast RAM to make up for it, it just couldn't shine.  Also, there's this investigation by legitreviews which attempts to answer this very question.

 

From those results, we see that the sweet spot for latency with DDR4 products available today is right at that 3000MHz/CL15 combination.  Bandwidth is a different story though, and it just continues to scale so we don't even know the limits of bandwidth on Skylake yet because they don't make RAM fast enough.  Right now the fastest RAM for sale on Newegg is DDR4 3400 CL16.  If you want to pump some extra volts into those sticks you can probably bring CL down to 15, but 3400 is still not fast enough to max out Skylake.  

[martin-w 3,240]

Thanks, much appreciated.

[WebMaximus 372]

Another question on memory and Skylake, is it important to fill up the memory slots for best performance or would filling only 2 of the 4 slots give you the same performance?

 

I'm currently on a Haswell @ 4.5 GHz using 16 GB DDR3 @ 2400 MHz so I already have a rather quick system and guess upgrading to a Skylake system would mostly be throwing my money in the lake (no pun intended :wink:) but at the same time the hardware enthusiast in me says 'Go for it' :smile:

 

And edited to add another question. Looking at the speed of DDR4 memory I've understood that the performance benefit in real world use such as P3D at speeds in excess of 2666 MHz is close to none. But what does the relation between CPU speed and memory speed look like on the Skylake platform with DDR4 memory?

 

What I mean is that should I decide to upgrade to a Skylake system I would of course try to get the CPU clock as fast as possible and as I recall it from the past increasing the CPU speed also increases the memory speed. Let's say I get the new CPU to 4.6 GHz and the memory will be @ 2666 MHz. I then find I can get my CPU even higher up to 4.8 GHz but what would then happen to the memory if they are already running at their full speed (2666 MHz) when the CPU is running @ 4.6 GHz?

 

Is that a scenario where I would have wished I got faster DDR4 memory to be able to use the memory at full speed hand-in-hand with the CPU?

 

And lastly, would I notice any difference in P3D between CL15 and CL16 DDR4 memory?

[martin-w 3,240]

Another question on memory and Skylake, is it important to fill up the memory slots for best performance or would filling only 2 of the 4 slots give you the same performance?

Prior to Skylake it was advisable to populate only two memory slots for max overclocking. Now however, with Skylake Asus have made enhancements so that all 4 slots can be populated without compromising overclocking.

 

 

What I mean is that should I decide to upgrade to a Skylake system I would of course try to get the CPU clock as fast as possible and as I recall it from the past increasing the CPU speed also increases the memory speed.

 

 

Not if you stick to just multiplier overclocking.

 

Now with Skylake, we have complete control over the BCLK. This is no longer tied to the PCIe and SATA timings. So we should be able to squeeze the most out of our CPU's without sending SATA and PCI timings bonkers.

 

So there's a choice, stick to multiplier overclocking or BCLK, or I presume both. I believe BCLK overclocking will still influence RAM as before, but one of the other lads more knowledgeable will need to educate us on that.

 

All in all though, overclocking will be back to the mega tweaking days for those enthusiastic fellows who fancy such endeavours.

 

For those who can't be arsed to squeeze out the last few megahertz, it  is only necessary to alter a few settings. Asus auto rules are rather good now, and based on thousands of hours of testing.

 

This is what JJ from asus says...

 

 

 

Many tweakers, tuners and overclockers make assumptions as to what they think need to be modified within the UEFI. In most cases when overclocking very little needs to be defined outside of enabling XMP, your multiplier, voltage type and the voltage target. If using our Auto Tuning technology then nothing needs to be modified. For users who are manually tuning once you have defined the previously noted parameters I strongly recommended in trusting the auto rules programmed into the board to adjust parameters such as VRM operation including phase response and loading policies as well as aspects like OCP. These type of parameters should ideally be left to auto values as they help to ensure superior stability. In fact we have found cases where users power configurations are less efficient or cause instability.

 

 

 

https://pcdiy.asus.com/2015/08/10-things-you-should-should-not-do-when-building-a-pc/

[DescendDescend 25]

I tried the Autotune and it wound the CPU up to 5Ghz in 100 Mhz increments before deciding the optimum was 4.8Ghz. The volts were still too high for my liking so I adjusted it for 4.6Ghz (at the moment).

[WebMaximus 372]

Ok, so with this said if I want 16GB I could go with either 4x4 or 2x8 and it won't matter looking at the performance?

 

And what about the speed of the memory, would I have anything to win choosing RAM with a higher speed than 2600 MHz?

 

As for Asus I've been a loyal customer of their's for many years now only buying top of the line products but after having a number of issues where the support and interest shown by Asus to address the issues have been everything but impressive I've decided to go with MSI for my next build to find out what they are like.

[aceridgey 330]

Ok, so with this said if I want 16GB I could go with either 4x4 or 2x8 and it won't matter looking at the performance?

 

And what about the speed of the memory, would I have anything to win choosing RAM with a higher speed than 2600 MHz?

 

As for Asus I've been a loyal customer of their's for many years now only buying top of the line products but after having a number of issues where the support and interest shown by Asus to address the issues have been everything but impressive I've decided to go with MSI for my next build to find out what they are like.

 

Hey buddy,

 

I've just build a new skylake system (from sandy) and I will answer any questions you have on skylake when I get it up and running.

 

I like ASUS but their customer care is absolutely terrible and their drivers outdated for slightly older products.

 

Alex

[martin-w 3,240]

I tried the Autotune and it wound the CPU up to 5Ghz in 100 Mhz increments before deciding the optimum was 4.8Ghz. The volts were still too high for my liking so I adjusted it for 4.6Ghz (at the moment).

The nice thing about Asus 5 way optimisation with Skylake, is that you can now select the max voltage, frequency or tempreture you are happy with and the auto tune won't go beyond that

 

 

My intention when I build and try the auto tune is to set the max temperature I'm happy with and let it do it's thing. Bearing in mind of course, that it measues CPU temp not core temp. Core temp is higher, while CPU temp is based on Intel's off-set method.

 

 

Ok, so with this said if I want 16GB I could go with either 4x4 or 2x8 and it won't matter looking at the performance?

 

And what about the speed of the memory, would I have anything to win choosing RAM with a higher speed than 2600 MHz?

 

As for Asus I've been a loyal customer of their's for many years now only buying top of the line products but after having a number of issues where the support and interest shown by Asus to address the issues have been everything but impressive I've decided to go with MSI for my next build to find out what they are like.

I know Asus boards now handle full memory slots without compromising overclock. Not sure about other makes.

 

For frequency, looks like 3000Mhz Cas 15 is optimal.

[WebMaximus 372]

Hey buddy,

 

I've just build a new skylake system (from sandy) and I will answer any questions you have on skylake when I get it up and running.

 

I like ASUS but their customer care is absolutely terrible and their drivers outdated for slightly older products.

 

Alex

Hi there Alex,

 

Cool, looking forward to it! What CPU, motherboard and RAM did you pick?

The nice thing about Asus 5 way optimisation with Skylake, is that you can now select the max voltage, frequency or tempreture you are happy with and the auto tune won't go beyond that

 

 

My intention when I build and try the auto tune is to set the max temperature I'm happy with and let it do it's thing. Bearing in mind of course, that it measues CPU temp not core temp. Core temp is higher, while CPU temp is based on Intel's off-set method.

 

 

 

I know Asus boards now handle full memory slots without compromising overclock. Not sure about other makes.

 

For frequency, looks like 3000Mhz Cas 15 is optimal.

After doing lots of reading about what RAM to pick for a Skylake system I think I'll go with maybe 2x8 GB 2400 CL14 sticks. Pretty much everything I've read says you won't see any real difference going higher than that and then you can invest the money you save on something else where you WILL notice a difference such as a new M.2 disk with read speed in excess of 2 GB/s...imagine what that would do for the loading time of P3D when you have thousands of AI models installed

 

As for Asus I'm sure there are some great features but I really had it with them and especially their software which feels most like early alpha versions in most cases.

[martin-w 3,240]

Fair enough, you're probably better clued up re RAM than me at the moment. Not much of a price diference though from what Iv'e seen here in the UK. 2400 to 3000 is only about £20.

 

Not had any trouble with Asus software here. Apart from Ai Suite being a bit slow to initially fire up. I understand how you'd be put off if you've had issues though.

 

Worth mentioning though that full fan optimisation and the same auto overclock is available in the Skylake UEFI now. no need to install the software.

[idahosurge 2]

This guy did some tests between 2 sticks of ram and 4.  Click on "2 vs 4 sticks" at the bottom of the table.

http://www.overclock.net/t/1570219/skylake-6700k-memory-tests-speed-vs-latency

 

So with a benchmark you do get better performance with 4 sticks on Skylake.  In the real world will the improvement actually be noticable!

[MarkW 1,493]

Hey buddy,

 

I've just build a new skylake system (from sandy) and I will answer any questions you have on skylake when I get it up and running.

 

I like ASUS but their customer care is absolutely terrible and their drivers outdated for slightly older products.

 

Alex

 

Alex,

 

Are you able to share your results.  I am currently on Sandy i2500K and really interested in what you have found.

[aceridgey 330]

Hi there Alex,

 

Cool, looking forward to it! What CPU, motherboard and RAM did you pick?

After doing lots of reading about what RAM to pick for a Skylake system I think I'll go with maybe 2x8 GB 2400 CL14 sticks. Pretty much everything I've read says you won't see any real difference going higher than that and then you can invest the money you save on something else where you WILL notice a difference such as a new M.2 disk with read speed in excess of 2 GB/s...imagine what that would do for the loading time of P3D when you have thousands of AI models installed

 

As for Asus I'm sure there are some great features but I really had it with them and especially their software which feels most like early alpha versions in most cases.

 

6700k, Asus Maximus  ranger VIII  and G skills 2x8GN 3000mhz ram

 

 

Alex,

 

Are you able to share your results.  I am currently on Sandy i2500K and really interested in what you have found.

 

Hi Mate,

 

I have found some bugs with my system, so I am currently sending back the parts to get it built by the guys there to see if they can solve the issues. I will report back when I have a stable system next week. Give me a nudge in 7days? 

[MarkW 1,493]

 

Hi Mate,

 

I have found some bugs with my system, so I am currently sending back the parts to get it built by the guys there to see if they can solve the issues. I will report back when I have a stable system next week. Give me a nudge in 7days? 

 

Will do.  That is my worst nightmare, I know enough just to be dangerous and luckily had no issues when I built my Sandy system but if something goes wrong its the computer building equivalent to CFIT for me.

[aceridgey 330]

Will do.  That is my worst nightmare, I know enough just to be dangerous and luckily had no issues when I built my Sandy system but if something goes wrong its the computer building equivalent to CFIT for me.

 

Tell me about it,

I've been so glad i've been working 60hour weeks just to get by not having the PC.. It's been in parts for a week. I am just glad I am taking it in to get professionally tested.

 

Alex