Tag Archives: skylake x

Casting an eye over the Intel i7 Skylake X editions.

Following on from our first look at the i9 7900X, we’ve now had a chance to take a look over a few more interesting chips from this enthusiast class range refresh. 

We have before us today two more chips with the first being the i7 7800X which is the replacement for the older 6800K, once more offering us 6 physical cores with hyper-threading giving us a total of 12 logical cores to play with. It’s running a 3.5GHz base clock and features an all core turbo of 4GHz although being the 6 core it offers us the most potential to overclock we’ve seen within this range.

The second chip we have here is the 7820X and on paper it looks to be the most interesting one for me on this generation due to its price to performance ratio. Replacing the 6900K from the previous generation but coming in for around £350 less, this chip offers 2 more cores and a higher all core turbo rating along with a 1/3rd more cache than the 7800X edition.

For reference the current price at time of writing for the 7800X is £359 and the 7820X currently retails for £530.

I’m not going to go too much into the platform itself this time around, I gave some background to the changes made on this generation including possible strengths and flaws back in the i9 7900K first look over here. If you haven’t already checked that out and wish to bring yourself up to speed, now is the time to do so before we go any further.

Everyone up to speed? Then let us begin.

The Long Hot Summer

The first question I had from the off was one of how are these going to handle given the heat we saw with the 10 core? The quick answer is surprisingly well compared to the earlier testing we carried out. The retail releases I’ve been playing around with here are allowing us to drop the voltages on them to almost half the level that we expected to see with the previous generation and certainly a  few notches lower than we saw in the earlier testing we carried out.

So whilst I did hope for some marked improvements on the final release I didn’t quite expect to see it quite so quickly, normally these sorts of improvements take a few months of manufacturing refinement to appear and its great we’re seeing this right now. It certainly gives me some confidence that we’ll be seeing improvements across the range over the coming batches and I’m now far more confident that the larger i9’s that they have already announced should hold up well when they do finally arrive with us in the future.

 If I was to give a rough outline of the state of these Skylakes i7’s I’d say they are still running maybe 10% hotter than the last generation Broadwell-E clock for clock. However Intel has these designed to throttle at 105 degrees, essentially giving it 10% more overhead to play with so they do seem to be confident in these solutions running that much hotter in use over the longer term.

One thing I noted in testing was that we were seeing a lot of micro-fluctuations across the cores when load testing. By that I mean we’d see temperatures bouncing up and down by anything up to 6 or 7 degrees as we tested, but never on more than a core or two at the time and it would be pulled straight back down again moments later only for another core to fluctuate and so on.

Behind this is Intels new PCU (Package Control Unit) that has been added to Skylake X series, and whilst I did note the ability to turn it off inside of the BIOS by doing so we’d also see some additional rise in the temperatures with it disabled. One of the strengths of the PCU and these new P-States appears to be the ability to load manage well and it actively aims to offer the smoothest experience as far as power saving goes. It’s certainly welcome as it does seem to offer more control over the allocation of system performance and doesn’t appear to be causing the same sort of C-State issues we saw when that first appeared so this looks to be another welcome feature addition at this time.

Once again we’re seeing the same sort of 99% CPU load efficiency across the board as we saw when testing in Cubase on the 7900X. This I suspect is in no small part down to the board and CPU trying their hardest to strike that power to performance balance I mention above and is great to see.

Hit The Bench

On to the figures then and first up the standard synthetics in the shape of Geekbench 4 and the CPU-Z benchmark.

7800K CPU-Z 4 @ 4.4GHz

7800X CPUZ test

7800K Geekbench 4 @ 4.4GHz

Geekbench 4 7800K

The obvious comparison here it to line it up against the previous generations 6 core solution. The 6800K saw Geekbench single core scores in the region of 4400 and multi core scores around the 20500 mark, meaning that these results are sitting in the 10% – 15% increase range which is pretty much where we expect a new generation to be.

7820K CPU-Z 4 @ 4.3GHz

i7 7820X CPUz

7820K Geekbench 4 @ 4.3GHz

7820X Geek4

In a similar fashion we can take a look at the last generation 6900K which had a Geekbench score in the 4200 range and the multi-core was sitting around the 25000 level. Once again we’re looking at around a 10% gain in these synthetics, which is pretty much in line with what we’d expect.

Hold the DAW

So far, so expected and to be honest the isn’t any real surprises to be had here as we start with the DAWBench DSP test.

Skylake i7 Dawbench 4

With the 7800X can see small gains over the previous 6800K chip which is just short of the 10% mark so even perhaps just a little lower than we would have expected. In fact in this test the 7820X offers similar modest gains over the older 6900K model and doesn’t do much to surprise here us here either.

7900x DawbenchVi

The DAWbench VI test tells a similar story at the lowest buffer setting with the 7800X and 7820X both sitting roughly where we expect. What proves to be the one point of interest beyond this however is that both chips scale better than their previous iterations once you move up to the larger buffer sizes. Whilst testing these chips much like the high-end 7900K, we saw them managing to hit CPU loads around the 99% mark, but you can see that each chip scaled upwards with better results overall when compared not only with their previous edition but also when placed up against the chip above them in the previous range. 

We saw a similar pattern with the Ryzen chips too and their infinity fabric design is similar in practice mesh design found in the Skylake X CPU’s. The point of these newer mesh style designs are to improve data transference within the CPU and allow for improved performance scalability, so with both firms looking to be moving firmly in this direction we can expect to see further optimizations from software developers in the future that should continue to benefit both platforms moving forward.

Conclusion

Looking towards the future and the are already plenty of rumours already circulating regarding the expectation of a “Coffee Lake” refresh coming next. This includes a new mid-range flagship that is shaping up to offer us a contender against the 7800X and might prove to be an interesting option for anyone looking for a new system around that level, but doesn’t currently find themselves needing to pick up a new system right away.

Also we’re expecting Threadripper to arrive with us over the next few months which is no doubt the comparison that a lot of people will be waiting on. It’ll be interesting to see if the scaling characteristics that were first exhibited by Ryzen get translated across to this newer platform.  

The entry level enthusiast chips have long  proven to be the sweet spot for those seeking the best returns on the performance to value curve when considering Intel CPU’s.  This time around however whilst the 7800X is a solid chip in its own right, it’s looking like the the extra money for the 7820X  could well offer a stronger bang per buck option for those looking to invest in a system around this level. 

Click here to can see the full range of Scan 3XS Audio Systems

Intel i9 7900X First Look

Intels i9 announcement this year felt like it pretty much came out of nowhere, and whilst everyone was expecting Intel to refresh its enthusiast range, I suspect few people anticipated quite the spread of chips that have been announced over the recent months. 

So here we are looking at the first entry to Intel’s new high-end range. I’ve split this first look into 2 parts, with this section devoted to the i9 7900X and some discussion of the lower end models as the full range is explained. I’ll follow up in the near future with a forthcoming post to cover the i7’s coming in below this model, just as soon as we have the chance to grab some chips and run those through the test bench too.

There has been a sizable amount of press about this chip already as it was the first one to make it out into the wild along with the 4 core Kabylake X chips that have also appeared on this refresh, although those are likely to be of far less interest to those of us looking to build new studio solutions.

A tale of two microarchitectures.

Kabylake X and Skylake X have both launched at the same time and certainly raised eyebrows in confusion from a number of quarters. Intels own tick/tock cycle of advancement and process refinement has gone askew in recent years, where the “high-end desktop” ( HEDT chips) models just as the midrange CPU’s at the start of this year have gained a third generation at the same 14nm manufacturing process level in the shape of Kabylake. 

Kabylake with the mid-range release kept the same 14nm design as the Skylake series before it and eaked out some more minor gains through platform refinement. In fact, some of the biggest changes to be found were in the improved onboard GPU found inside of it rather than the raw CPU performance itself, which as always is one of the key things missing in the HEDT edition. All this means that whilst we have a release where it’s technically two different chip ranges, the isn’t a whole lot left to differentiate between them. IN fact given how the new chip ranges continue to steam ahead in the mid-range, this looks like an attempt to help bring the high-end options back up to parity with the current mid-range again quickly which I think will ultimately help make things less confusing in future versions, even if right now it has managed to confuse things within the range quite a bit.

Kabylake X itself has taken a sizable amount of flak prior to launch and certainly appears to raise a lot of questions on an initial glance. The whole selling point of the HEDT chip up until this point has been largely more cores and more raw performance, so an announcement of what is essentially a mid-range i5/i7 grade 4 core CPU solution appearing on this chipset was somewhat of a surprise to a lot of people. 

As with the other models on this chipset range, the 4 cores are being marketed as enthusiast solutions, although in this instance we see them looking to capture a gaming enthusiast segment. The have been some early reports of high overclocks being seen, but so far these look to be largely cherry-picked as the gains seen in early competition benchmarking have been hard to achieve with the early retail models currently appearing.

Whilst ultimately not really of much interest in the audio & video worlds where the software can leverage far more cores than the average game, potentially the is a solid opportunity here for that gaming market that they appear to be going after if they can refine these chips for overclocking over the coming months. However early specification and production choices have been head-scratchingly odd so far, although we’ll come back to this a bit later.

Touch the Sky(lake).

So at the other end of the spectrum from those Kabylake X chips is the new current flagship for the time being in the shape of the Skylake 7900X. 10 physical cores with hyper-threading give us a total of 20 logical cores to play with here. This is the first chip announced from the i9 range and larger 12,14,16,18 core editions are all penciled in over the coming year or so, however, details are scarce on them at this time.

intel-core-x-comparison-table

At first glance, it’s a little confusing as to why they would even make this chip the first of its class when the rest of the range isn’t fully unveiled at this point. Looking through the rest of range specifications alongside it, then it becomes clear that they look to be reserving the i9’s for CPU’s that can handle a full 44+ PCIe lane configuration. These lanes are used for offering bandwidth to the connected cards and high-speed storage devices and needless to say this has proven a fairly controversial move as well.

The 7900X offers up the full complement of those 44 lanes although the 7820X and 7800X chips that we’ll be looking at in forthcoming coverage both arrive with 28 lanes in place. For most audio users this is unlikely to make any real difference, with the key usage for all those lanes often being for GPU usage where X16 cards are the standard and anyone wanting to fit more than one is going to appreciate more lanes for the bandwidth. With the previous generation we even tended to advise going with the entry level 6800K for audio over the 6850K above it, which cost 50% more but offered very little of benefit in the performance stakes but did ramp up the number of available PCIe lanes, choosing instead to reserve this for anyone running multiple GPU’s in the system like users with heavy video editing requirements. 

Summer of 79(00X)

So what’s new?

Much like AMD and their infinity fabric design which was implemented to improve cross-core communication within the chip itself, Intel’s arrived with its own “Mesh” technology.

Functioning much like AMD’s design, it removes the ring based communication path between cores and RAM and implements a multi-point mesh design, brought in to enable shorter paths between them. In my previous Ryzen coverage I noted some poor performance scaling at lower buffer settings which seemed to smooth itself out once you went over a 192 buffer setting. In the run-up to this, I’ve retested a number of CPU’s and boards on the AMD side and it does appear that even after a number of tweaks and improvements at the BIOS level the scaling is still the same. On the plus side, as it’s proven to be a known constant and always manifests, in the same manner, I feel a lot more comfortable working with them now we are fully aware of this.

In Intels case I had some apprehension going in that given it is the companies first attempt at this in a consumer grade solution and that perhaps we’d be seeing the same sort of performance limitations that we saw on the AMD’s, but so far at least with the 7900X the internal chip latency has been superb. Even running at a 64 buffer we’ve been seeing 100% CPU load prior to the audio breaking up in playback, making this one of the most efficient chips I think I’ve possibly had on the desk.

i9 CPU load

 

So certainly a plus point there as the load capability seems to scale perfectly across the various buffer settings tested.

RAW performance wise I’ve run it through both CPU-Z and Geekbench again.CPU-Z 7900X

Geekbench 4 7900X

GeekBench 4

The multi-core result in Geekbench looks modest, although it’s worth noting the single core gains going on here compared to the previous generation 10 core the 6950X. On the basic DAWBench 4 test this doesn’t really show us up any great gains, rather it returns the sort of minor bump in performance that we’d kind of expect.

DAWBench 4 7900X

However whilst more cores can help spread the load, a lot of firms have always driven home the importance of raw clock speeds as well and once we start to look at more complex chains this becomes a little clearer. A VSTi channel with effects or additional processing on it needs to be sent to the CPU as a whole chain as it proves rather inefficient to chop up a channel signal chain for parallel processing.

A good single core score can mean slipping in just enough time to be able to squeeze in another full channel and effects chain and once you multiply that by the number of cores here, it’s easy to see how the combination of both a large number of cores and a high single core score can really translate into a higher total track count and is something we see manifest in the Kontakt based DAWBench VI test.

 

 

In this instance the performance gains over the previous generation seems quite sizable and whilst there is no doubt gains have been had from a change in architecture and that high-efficiency CPU usage we’ve already seen it should be noted here that this is close to a 20% increase in clock speed in play here too.

When we test we aim to do so around the all core turbo level. Modern Intel CPU’s have two turbo ratings, one is the “all core” level to which we can auto boost all the cores if the temperatures are safe and the other is the “Turbo 3.0” mode where it boosts a single core or it did in previous generations, but now we see it boosting the two strongest cores where the system permits.

The 7900X has a 4.5GHz 2 core turbo ability of 4.5GHz but we’ve chosen to lock it off at the all core turbo point in the testing. Running at stock clock levels we saw it boost the two cores correctly a number of times, but even under stress testing the 2 core maximum couldn’t be hit constantly without overheating on the low noise cooling solution we are using. The best we managed was a constant 4.45GHz at a temperature we were happy with, so we dialed it back to all core turbo clock speed of 4.3GHz across all cores and locked it in place for the testing, with it behaving well around this level. 

It’s not uncommon for a first few batches of silicon on any new chip range to run a bit hot and normally this tends to get better as the generation gets refined. It’s the first time we’ve seen these sorts of temperatures on a chip range however and the is a strong argument to be made for going with either one of the top 2 or 3 air coolers on the market currently or defaulting to a water loop based cooling setup for any machine considering this chip. In a tower case this shouldn’t prove a problem but for rack systems, I suspect the 7900X might prove to be off-limits for the time being.

I’d fully expect the i7’s that are going to come in below it to be more reasonable and we should know about that in the next update, but it does raise some questions regarding the chips higher up in the i9 range that are due with us over the next 12 months. The has already been some debate about Intel choosing to go with thermal paste between the chip and the heatsink, rather than the more effective soldering method, although early tests by users de-lidding their chips hasn’t returned much more than 10 degrees worth of improvement, which is a fairly small gain for such a drastic step. We can only hope they figure out an improved way of improving the chips thermal handling with the impending i9’s or simply return to the older soldered method, otherwise, it could be quite some time until we see the no doubt hotter 12+ core editions making it to market.

Conclusion

In isolation, it looks fine from a performance point of view and gives the average sort of generation on generation gains that we would expect from an Intel range refresh, maybe pumped up a little as they’ve chosen to release them to market with raised base clocks. This leaves little room for overclocking, but it does give the buyer who simply wants the fastest model they can get out of the box and run it at stock.

The problem is that this isn’t in isolation and whilst we’ve gotten used to Intel’s 10% year on year gains over recent generations, there has to be many a user who longs for the sort of gains we saw when the X58 generation arrived or even when AMD dropped the Athlon 64 range on us all those years ago.

Ryzen made that sort of gain upon release, although they were so far behind that it didn’t do much more than breaking them even. This refresh puts Intel in a stronger place performance wise and it has to be noted that this chip has been incoming for a while. Certainly since long before Ryzen reignited the CPU war and it feels like they may have simply squeezed it a bit harder than normal to make it look more competitive.

This isn’t a game changer response to AMD. I doubt we’ll be seeing that for a year or two at this point and it will give AMD continued opportunities to apply pressure. What it has done however is what a lot of us hoped for initially and that it is forcing Intel to re-examine its pricing structure to some degree.

What we have here is a 10 core CPU for a third cheaper than the last generation 10 core CPU they released. Coming in around the £900 it rebalances the performance to price ratio to quite some degree and will no doubt once more help make the “i” series CPU’s attractive to more than a few users again, after a number of months of it being very much up for debate in various usage segments. 

So will the impending AMD Threadripper upset this again?

I guess we’re going to find out soon enough over the coming months, but one thing for sure is that we’re finally seeing some competition here again, firstly on pure pricing but surely this should be a safe bet for kick-starting some CPU advancements again. This feels kinda like the Prescott VS Athlon 64 days and the upshot of that era was some huge gains in performance and solid improvements being made generation upon generation.

The cost and overall performance here keeps the 7900X in the running despite its obvious issues, and that raw grunt on offer makes it a very valid choice where the performance is required. The only real fly in the ointment is the heat and noise requirements most audio systems have, although hopefully as the silicon yields improve and refine this will mature into a cooler solution than it is now. It’s certainly going to be interesting to see how this pans out as the bigger models start making it to market over the coming year or so and of course with the smaller i7 brethren over the coming days.

Previous DAWBench Testing Results

To see our complete audio system range @ Scan