CPU Reviews System

Skylake-X review: Intel Core i9-7900X and the X299 platform

Introduction Intel's new X-Series consists of i5, i7, and reissued i9 processors, all of which require the same X299 chipset that comes with the LGA2066 socket. The S-series processors will continue to be used with the 200 chipset. In some applications and games, we've encountered performance trends that didn't match our expectations. Considering that Skylake X has a speed advantage due to higher clock speeds as well as new architectural... Intel has reduced the shared Last Level Cache (LLC-L3) and transferred it from an inclusive to a non-inclusive (but exclusive) approach. This was done with the help of an efficient caching algorithm that improves the hit rate of the L2 cache ... The Basin Falls X299 chipset The Kaby Lake-X and Skylake-X processors sit in an LGA2066 socket (R4), powered by an X299 chipset with 6 watts of power, underscoring Intel's strategy of using server chipsets for their HEDT- Li... Why should it always only hit AMD when a change of architecture leads to application-specific "collapses" in the expected performance or, more simply put, the CPU in certain applications simply does not... Ashes of the Singularity: Escalation Because we were just so nice, we continue the high-altitude flight of the overclocked Core i7-6950X, because even with this benchmark the optimization problem described above is very clear:... Grand Theft Auto V (DX11) GTA V restores the old pecking order and also shows two things. First, it's still an Intel domain, but AMD has made up for it with the Ryzen CPUs! It's really amazing how to deal with some fine... Project Cars (DX11) Even with Project Cars, the chemistry between the new CPU and the engine is right, even though it was observed time and again that all 10 cores clocked up to 4.0 GHz, even though they were not all busy. But we would... Introduction During the launch article of AMD's Ryzen 7 CPUs, we had already explained all workstation and HPC benchmarks in great detail and also questioned the background for many results in some cases even down to the last detail. En... Important preliminary remark Since Intel no longer realizes the contact between Die and Heatspreader by metallic solder at Skylake-X and Kaby Lake-X, but also uses cheaper TIM (Thermal Interface Material) to use the same way. Cooling with the Chiller crowbar In order to be able to achieve usable (overclocking) results, we had to switch from the normal water cooling to the Alphacool Ice Age Chiller 2000, as already mentioned in the previous chapter. ... What is left for us after all these pages as a summary? Intel's market leadership in recent years is ultimately based on a continuous offer of more or less large updates, which of course also this time a certain amount of expected...

Introduction

Intel's new X-Series consists of i5, i7, and reissued i9 processors, all of which require the same X299 chipset that comes with the LGA2066 socket. The S-series processors will continue to be connected to the 200 chipset, while Intel's new X-Series has been specifically designed for the high-end desktop (HEDT) segment, which targets enthusiasts and content producers. The X-Series offers the full range, from four-core chips to 18-core models that can run 36 threads. Intel is also looking for some architectural improvements that will deliver up to 15 percent more performance in single-threaded applications and a performance boost of about 10 percent for multi-core applications.

Intel's dominance began more than 10 years ago, and since then it has created a comparatively one-sided and boring CPU market. Without significant competition, Intel's optimization schedule consisted not of discounts, radically new architectures, or a sharp increase in the number of CPU cores, but only of maintaining the status quo. Now, however, AMD has become a (new) competitor again. Ryzen processors are ploughing through the market with new thread numbers, SMT, an aggressive pricing model, and multipliers released across all processor versions. Unfortunately, AMD did not initiate the price war in the middle class – which is what we had hoped for. Intel, on the other hand, has maintained its prices despite the intensifying competition. All the greater was our joy at the price reductions in the Ryzen 7 range.

So far, Intel's expensive HEDT lineup has served as a kind of crown jewel in the desktop market, and– almost more importantly for the manufacturer, they have also generated huge profits. As a result, we expect Intel to vigorously defend its HEDT segment and breathe new life into the word competition. AMD could further shake up this current status quo with its recently announced Threadripper chips, which feature up to 16 cores (32 threads) and 64 PCIe 3.0 lines on all models, which is in stark contrast to Intel's clear product boundaries. AMD has not yet announced the price model for the Threadripper, but we expect it to be good value for money.

While it seems that Intel is reacting to the new competition with the X Series, the broader HEDT offering was already planned before this time and thus also Ryzen. The architectural improvements were certainly not broken. Due to the way semiconductor manufacturing is made, architectural improvements take a longer time to find their way into the desktop PC. Probably not least because of this, Intel has not yet released any specifications for the new Core i9 models with the maximum number of possible cores, which will not be released until October. As a result, Intel appears to have spruced up the X Series in response to AMD's Threadripper announcement. In addition, the prices for the HEDT line-up have been significantly reduced, which is also not a common measure on the part of Intel.

The 12+ core models based on the Skylake X architecture are still a long way off, and our Core i7-7740X inexplicably delays delivery. Thus, we first rely on the ten-core model Core i9-7900X in our benchmarks and will later publish the further product range in tests step by step.

Kaby Lake-X Models

We are not used to simpler i5 and i7 models in the HEDT line-up, which are clearly below the new i9 models, because normally the chips of this series always fell one or two generations behind the mass-market versions. The Kaby Lake X for the X299 chipset breaks with this quad-core paradigm, but the rest of the series is still based on the Skylake architecture. But that could soon change. Earlier this year, Intel announced a new "Data Center First" strategy to use the latest manufacturing processes to first use the Xeon models before using them for desktop chips. Considering that HEDT processors are composed of cores of server chips, HEDT is likely to be at the forefront in the future.

Intel expands its HEDT offering from four to nine processors, but the two Kaby Lake X versions, which are manufactured in a 14nm+ process, look like a somewhat curious addition. They only support two storage channels, while the Skylake-X counterparts have memory controllers that are based on four memory channels. This means that only half of the eight possible memory locks can be installed on the two Kaby Lake X models. The lower number of PCIe lanes results in limited I/O capabilities. Intel disables the HD Graphics 630 GPU, which now serves as a dark piece of silicon to absorb waste heat, supposedly enabling greater heat tolerance for overclocking. Apart from a slightly increased base clock and a larger TDP of 112 W, the i5-7640X and i7-7740X are similar to their S-Series counterparts. Ultimately, this also reflects pricing.

However, the idea of linking a "budget" processor to an expensive motherboard evokes similar associations to the Core i3-7350K at the time, which for the same reasons is not a great success. Intel told us that motherboard manufacturers now have the opportunity to develop a low-cost X299 board specifically for the Kaby Lake X chips – but so far nothing has arrived in this direction. At this point, Intel is betting on an entry point to make it easier to upgrade at a later date. We will address this topic with our own Kaby Lake X review.

 

Core i5-7640X

Core i7-7740X

Core i7-7800X

Core i7-7820X

Core i9-7900X

Core i9-7920X

Core i9-7940X

Core i9-7960X

Core i9-7980XE

Chip

Kaby Lake-X

Kaby Lake-X

Skylake-X

Skylake-X

Skylake-X

Skylake-X

Skylake-X

Skylake-X

Skylake-X

Process

14nm+

14nm+

14nm

14nm

14nm

       

Cores/Threads

4/4

4/8

6/12

8/16

10/20

12/24

14/28

16/32

18/36

Base clock (GHz)

4.0

4.3

3.5

3.6

3.3

?

?

?

?

Intel TurboBoost 2.0 Frequency (GHz)

4.2

4.5

4.0

4.3

4.3

?

?

?

?

Intel TurboBoost 3.0 Frequency (GHz)

Na

Na

Na

4.5

4.5

?

?

?

?

L3 Cache

6

8

8.25

11

13.75

?

?

?

?

PCIe 3.0 Lanes

16

16

28

28

44

?

?

?

?

Memory. Support

Dual Channel DDR4-2666

Dual Channel DDR4-2666

Quad Channel DDR4-2400

Quad Channel DDR4-2466

Quad Channel DDR4-2666

?

?

?

?

Tdp

112W

112W

140w

140w

140w

?

?

?

165W

Socket

2066

2066

2066

2066

2066

2066

2066

2066

2066

Chipset

X299

X299

X299

X299

X299

X299

X299

X299

X299

Free multiplier

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Delivery price (USD, 1000 pieces)

$242

$339

$389

$599

$999

$1,199

$1,399

$1,699

$1,999

Intel has improved memory support compared to previous Broadwell E chips on all Skylake X models except the i7-7800X. They now comply with the DDR4-2666 and no longer the DDR-2400 standard. However, EEC support is dispensed with, ultimately to prevent Xeon buyers from switching to the desktop platform. More detailed specifications have not yet been announced, but we suspect they are similar. We also suspect that the clock frequencies decrease with increasing core numbers.

Active Cores

1

2

3

4

Cores 5-10

Intel Core i9-7900X (GHz) TurboBoost

4.3

4.3

4.1

4.1

4.0

The Core i9-7900X uses the same TurboBoost 2.0 (TB) as its predecessor, but the clock frequencies are noticeably higher and can reach up to 4.0 GHz at ten activated cores. Six of the Skylake X models also offer TB 3.0. The feature has been reworked by Intel and now uses the two fastest cores when workloads need to be processed with only a few threads, which is a significant improvement over the past. TurboBoost 3.0 clocks two "favorite cores" as tandems of up to 4.5 GHz, while the remaining cores remain at the speed of TB 2.0. This should speed up Intel's IPCs with additional speed. This is one of the typical performance deficits in workloads with only a few threads to be tackled, from which HEDT CPUs have suffered so far. TB 3.0 requires an additional driver for some motherboards, which we also installed. Intel, however, plans native support on Windows 10 to eliminate user intervention at this point.

Intel also introduces partial AVX-512 support, which means that the 18-core flagship is the first home processor to provide theoretical computing power from a teraflop. The manufacturer has also redesigned the cache hierarchy. While increasing the capacity of the L2 cache, the L3 cache has been reduced, which should improve performance for some applications. In addition, Intel's new 2D mesh architecture is making its debut, but like AMD's new infinity fabric technology, it still triggers some toothache. However, we will look into this topic in more detail on the following pages.

Intel is also cutting prices for its new chips. If the Broadwell-E i7-6950X still cost 1723 dollars, the price of the i7-7900X with its ten cores drops to 1000 dollars. The price tag for an eight-core CPU no longer has 1089 dollars, but 599 dollars. That's still significantly more expensive than AMD's Ryzen 7 1800X, whose eight cores are available for 500 dollars. Looking at the entire Ryzen series, Intel also has to compete with the Ryzen 7 1700, which also has eight cores and 16 threads, but costs only 330 dollars. The price for Intel's six-core swells drops from 583 to 339 dollars – the Ryzen 5 1600X is already available for 249 dollars, the Ryzen 5 1600 costs 219 dollars, and both chips offer six CPU cores. Of course, the same number of CPU cores does not mean the same performance. At this point, the Intel chips should deliver a little more power per core.

Intel is lowering the prices of mid-range HEDTs, but those who value 44 PCIe lanes will need to invest at least 999 dollars. Memory migrates to the PCIe bus, and while multi-GPU configurations are no longer as popular as they used to be, this is still a high entry hurdle. Intel also offers a new PCIe Virtual RAID on CPU (VROC) that allows it to merge up to 20 SSDs in one bootable volume. Remarkably, this RAID array can be built on any available PCIe socket, while the previous RSTe RAID required a connection to the chipset. Bypassing the chipset eliminates the usual bandwidth restrictions of the DMI bus, but that has a price. Unfortunately, you need to purchase an upgrade key that needs to be plugged into the motherboard to unlock the VROC feature. Server motherboards are a widely used method, but they will not meet with much opposition even among the most demanding home users. Intel has not yet commented on prices and specifics, but we expect a significant surcharge.

With the dive into the Tests, we came across some strange performance tendencies over the past week. The launch undoubtedly seems like a small catalyst, where everyone has just given the right gas, but many questions remain unanswered. Although motherboard firmware updates (from different vendors) addressed many of these oddities, we believe that some of these abnormalities will (remain) (for the time being). It seems that Intel's Skylake X models, similar to AMD's Ryzen processors, still have a period of optimization. So let's take a look at the factors that affect Skylake-X performance so much.

Danke für die Spende



Du fandest, der Beitrag war interessant und möchtest uns unterstützen? Klasse!

Hier erfährst Du, wie: Hier spenden.

Hier kannst Du per PayPal spenden.

About the author

Igor Wallossek

Editor-in-chief and name-giver of igor'sLAB as the content successor of Tom's Hardware Germany, whose license was returned in June 2019 in order to better meet the qualitative demands of web content and challenges of new media such as YouTube with its own channel.

Computer nerd since 1983, audio freak since 1979 and pretty much open to anything with a plug or battery for over 50 years.

Follow Igor:
YouTube Facebook Instagram Twitter

Werbung

Werbung