The Core Wars


PC & Tech Authority - - REVIEWS -

I ntel’s re­sponse to AMD’s Ryzen 7 ten­core CPU came faster than any­body could have imag­ined. At this year’s Com­pu­tex, the com­pany an­nounced the new Core-X se­ries of pro­ces­sors, based on the Sky­lake-X and Kaby-Lake X ar­chi­tec­tures. Now, In­tel had orig­i­nally planned to re­lease Sky­lake-X at the end of this year, or even early 2018, so rush­ing it for­wards by six months means it likely hasn’t un­der­gone the rig­or­ous test­ing that In­tel usu­ally does, as we’ll dis­cuss soon. How­ever, it does mean that it has a range of new prod­ucts that com­pete with the Ryzen pro­ces­sor, though purely on per­for­mance, not price. It’s a rather odd launch, with Sky­lake-X be­ing a rel­a­tively ma­jor up­grade to In­tel’s de­sign, while Kaby-Lake X isn’t. Let’s see what’s the deal with Sky­lake-X first.


There will be nine new CPUs in the Core-X fam­ily, but cur­rently only five have launched. The top seven CPUs are all based on the Sky­lake-X de­sign, while the bot­tom two use Kaby-Lake X. The fastest chip cur­rently avail­able is the ten-cored, 20-threaded i9-7900X, which cur­rently re­tails for around $1,440. That’s still dou­ble the price of AMD’s ten-cored, 20-threaded Ryzen 7 1800X, so it had bet­ter run rings around AMD to jus­tify the price hike.

The i9-7900X is built on the same 14nm en­hanced process of In­tel’s pre­vi­ous gen­er­a­tion of CPUs, but the com­pany won’t sup­ply info on how many tran­sis­tors it has. Even­tu­ally we’ll see the re­lease i9-7980XE, which will have a whop­ping 18 cores, but un­til now the i9-7900X is the top of the line. It has a base fre­quency of 3.3GHz, but can Turbo up to 4.3GHz. Just like AMD, In­tel has in­cor­po­rated a sec­ond level of Turbo called Turbo Boost Max 3.0, which the­o­ret­i­cally brings the CPU speed up to 4.5GHz if the ther­mal con­di­tions are right. We say the­o­ret­i­cally, as it didn’t work on three of the four motherboards we tested – ev­ery time we tried to in­stall the nec­es­sary driv­ers, we’d en­counter an er­ror say­ing “ITBM Driver not Avail­able Ex­ist­ing Ap­pli­ca­tion”.

As a re­sult, all of our boards – bar the MSI X299 Gam­ing Pro Car­bon AC – were lim­ited to 4.3GHz, even when we tried to over­clock them us­ing their au­to­matic over­clock­ing fea­tures. Only the MSI board worked cor­rectly, hit­ting 4.5GHz dur­ing our test­ing. There’s ob­vi­ously some work to be done on the driver and BIOS sup­port for this fea­ture.

With ten cores, this chip is a bit of a power-hog, with a max TDP of 140W and an op­er­at­ing volt­age around 1.7V. You’ll need to bring your own cool­ing too; we used the Cor­sair H105. The i9-7900X brings plenty of PCIe 3.0 lanes to the ta­ble, with a max­i­mum of 44. How­ever, as you progress down the stack, the num­ber of lanes drops, to 28 on the i7-7820X and then 16 on the I7-7740X.

Sky­lake X has had some rather sig­nif­i­cant changes to its de­signs. For starters, In­tel has ditched the Ring topology it used to con­nect the cores in the past, and now uses what it calls a ‘mesh in­ter­con­nect’ tech­nol­ogy. Ap­par­ently this al­lows for lower la­tency be­tween each core, as well as higher band­width be­tween each core.

In­tel has also shifted the caches around. Now each core gets a full 1MB of L2 cache, up from 256kB on the pre­vi­ous high-end CPUs. The band­width be­tween the L1 and L2 caches has been in­creased to 128 bytes per cy­cle, which In­tel claims quadru­ples the as­so­cia­tiv­ity be­tween the cache from four to 16. Not all caches have been in­creased though, with In­tel drop­ping the last level of cache from 2.5MB per core down to 1.375MB.


The other CPU sent to us was the i7-7740X, which uses the Kaby-Lake X de­sign. This is a far less in­ter­est­ing CPU, as it’s ba­si­cally iden­ti­cal to the i7-7700 with the ex­cep­tion of the new form fac­tor, yet costs $30 more at $500. All of the new Core-X CPUs have 2066 pins, to fit into the new LGA 2066 socket on the ac­com­pa­ny­ing X299 chipset that Core-X must be used for. Un­for­tu­nately the new pin count, which is 55 higher than the last gen­er­a­tion, means you won’t be able to use your old X99 board for any of the Core-X CPUs.

Like the i7-7700K, it’s a quad-cored CPU with Hy­per-Thread­ing. Un­like the higher-end Core-X CPUs, there’s no sup­port for the new Turbo Boost Max 3.0, in­stead re­ly­ing on the stan­dard boost to hit 4.5GHz. The num­ber of PCIe lanes has been slashed com­pared to up­perend Core-X CPUs, with just six­teen to play with. Un­like the i9-7900X, this CPU only sup­ports dual chan­nel me­mory as op­posed to the quad-chan­nel me­mory of the other CPU. So, that X299 mother­board you’ll need to buy, which comes with eight me­mory slots, will see four of them go to waste. Also, the in­te­grated graph­ics of the i7-7700K have been dis­abled, which doesn’t make a great deal of sense to us. Of the 2066 pins on the chip, about 1000 of them aren’t even used.


Un­like AMD, who gen­er­ally like to keep their new CPUs com­pat­i­ble with ex­ist­ing mother­board chipsets for as long as pos­si­ble, In­tel loves to re­lease a new chipset with each new CPU re­lease. In the case of the Core-X it’s the X299 chipset, which fea­tures the new LGA 2066 socket. It also sup­ports quad-chan­nel me­mory,

with an o cial fre­quency of DDR42666MHz, and a max­i­mum amount of 128GB. How­ever, some Core-X CPUs only o cially sup­port DDR4-2400MHz, such as the

It’s worth point­ing out that Ryzen’s new chipset is the X399, so try not to buy the wrong chipset when you’re buy­ing a board for your Core-X. We think this is a bit cheeky of AMD, as it sim­ply con­fuses cus­tomers.

One of the main di”er­ences with the new X299 over the pre­vi­ous X99 chipset is the use of a High Speed IO de­sign, which it used to only o”er on its Z se­ries of motherboards. This makes the chipset act like one large switch; the DMI 3.0 link from the CPU is ba­si­cally a PCIe 3.0 x 4 link, and the chipset it­self could sup­port up to 24 lanes of PCIe 3.0. Mother­board mak­ers would then use the PCIe lanes from the chipset for the likes of M.2 slots, USB, and Eth­er­net.

X299 now uses the same de­sign, and in­creases the DMI 2.0 of the X99 to the speed of the DMI 3.0 of the Z-se­ries. This is a large in­crease in band­width, which is why the top-end Core-X CPUs now o”er up to 44 lanes of PCIe 3.0 to play with. This will al­low mother­board man­u­fac­tur­ers much more flex­i­bil­ity in terms of the num­ber of M.2, USB, SATA and other fea­tures.

X299 also sup­ports In­tel’s new Op­tane hard drive caching tech­nol­ogy; though that’s not re­ally a huge ben­e­fit given our is­sues test­ing Op­tane in the past. Hope­fully the tech­nol­ogy will ma­ture to the point where it’s sim­ple plug and play, with­out the need for spe­cial disk for­mat­ting or only sup­port­ing the main OS drive.

In terms of con­nec­tiv­ity, X299 na­tively sup­ports ten USB 3.0 and eight SATA 3 ports. We’ll ob­vi­ously see ven­dors in­creas­ing this though, given how many PCIe lanes they have to work with now. The X299 also in­cludes In­tel’s new Vir­tual Raid on CPU (VROC), but there’s a catch. You’ll have to pay ex­tra for a tiny key that in­serts into the mother­board to en­able it. Given that it ap­pears VROC sup­port is al­ready built into the CPU and X299, this seems rather stingy. It is rather cool tech though, al­low­ing up to twenty drives to be synched into one bootable RAID ar­ray.


Ev­ery Core-X CPU will ship fac­tory un­locked, while the X299 chipset sup­ports full mul­ti­plier and base clock fre­quency ad­just­ments. This means over­clock­ers should have a field day with this chip, al­though it does seem that In­tel has once again used paste be­tween the heat spreader and the sil­i­con, so delid­ding will likely be­come pop­u­lar amongst ex­treme over­clock­ers. Cur­rently the world record for Core-X over­clock is 5.7GHz, us­ing LN2 cool­ing and an Asus Ram­page mother­board. We no­ticed on all of our boards that there’s an ex­tra 4-pin power in­put on the board; we’re not sure if this is for over­clock­ers, or for the up­com­ing 18core be­he­moth.


As our bench­marks show, in many in­stances, the i9-7900X had a size­able lead in per­for­mance over the Ryzen 7 1800X. Yet there were also a hand­ful where AMD’s chip wasn’t too far be­hind, which is very im­pres­sive con­sid­er­ing it’s half the price. There’s also the is­sue of the cost of motherboards; it’s pos­si­ble to buy a Ryzen 7 com­pat­i­ble board for around $250, while X299 boards start around the $450 point. There­fore the to­tal cost of own­er­ship for a Ryzen 7 1800X sys­tem is less than half that of the In­tel i9-7900X sys­tem.

If you’re look­ing for the ul­ti­mate in per­for­mance, there’s no deny­ing that the i9-7900X is cur­rently the fastest con­sumer CPU on the desk­top. How­ever, if you’re look­ing for a de­cent bal­ance be­tween price and per­for­mance, the Ryzen 7 1800X puts up a de­cent fight for half the cost, so your de­ci­sion is go­ing to be based en­tirely on bud­get.

We en­coun­tered this er­ror with three of the four boards when try­ing to use Turbo Boost Max 3.0

Newspapers in English

Newspapers from Australia

© PressReader. All rights reserved.