Thursday, August 21st 2014

Intel Core i7-5820K Features Fewer PCI-Express Lanes After All

It turns out that our older report suggesting that the most affordable of Intel's new Core i7 "Haswell-E" HEDT processors will feature a slimmer PCI-Express root complex, even if it gives you 6 cores at a [hopefully] sub-$400 price-point, holds true, after all. Intel's wacky approach to its latest HEDT processor lineup was confirmed by leaked manuals of Gigabyte's socket LGA2011-3 motherboards, based on the Intel X99 Express chipset. The manual confirms that while Intel's $500-$750 Core i7-5930K and >$1,000 Core i7-4960X offer bigger 40-lane PCI-Express Gen 3.0 root complexes; the Core i7-5820K features a narrower 28-lane one. This means that multi-GPU configurations on systems running the chip won't be too different from those on LGA1150 "Haswell" platforms.

On motherboards with, say, three PCI-Express 3.0 x16 slots, the i7-5930K and i7-5960X will let you run two slots at full x16 bandwidth, and a third slot at x8. On systems with the i7-5820K, the second slot won't go beyond x8, and the third one will cap out at x4. On boards with four slots, one of them will run out of bandwidth. The trade-off for this narrower PCI-Express interface is the fact that you're getting six "Haswell" cores, twelve logical CPUs enabled with HyperThreading, about 12 MB of L3 cache, and a quad-channel DDR4 memory interface, at a price-point not too far off from the Core i7-4790K. So for enthusiasts with no more than two high-end graphics cards, the i7-5820K could provide an attractive gateway option to Intel's new HEDT platform. You can find the leaked manuals in this thread.
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52 Comments on Intel Core i7-5820K Features Fewer PCI-Express Lanes After All

#1
HumanSmoke
So, the obvious route to take is to pair the cheaper CPU with a PLX 8747 bridge chip equipped board. The lane extender option is already used on selected X79 boards so I can't see mobo makers missing out on the obvious marketing opportunity with X99.
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#2
shb-
This could be wrong, but i think three x8 slots (24 lanes) should be fine for triple sli/cf. After all, pci-ex v3 provides double bandwidth per line comparing to pci-ex v2 we all used not so long ago. So basically pci-ex v3 x8 slot is the same as v2 x16 slot.
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#3
jchambers2586
I will never buy a E platform Intel screws these users over the worst. Going to start using WS boards from ASUS if I need more PCIE lanes.
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#4
HumanSmoke
by: shb-
This could be wrong, but i think three x8 slots (24 lanes) should be fine for triple sli/cf. After all, pci-ex v3 provides double bandwidth per line comparing to pci-ex v2 we all used not so long ago. So basically pci-ex v3 x8 slot is the same as v2 x16 slot.
The lane assignments would be OK for CrossfireX, but Nvidia require a minimum of 8 lanes per card for SLI. As the article states, the slot assignments are 1 @ x16, 1@ x8, 1 @ x4 , so the only way to circumvent the lane restriction for the 5820K- not just for triple cards but to remove limitations for I/O and storage options is to use lane extenders as many current enthusiast and workstation class boards do.
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#5
Ferrum Master
This is money milking again...

Monopoly remains monopoly....
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#6
lilhasselhoffer
Slow clap for Intel....


We've discussed this ad nauseam with the socket 2011 offerings, Intel offers PCI-e lanes to make up for not having some features baked in. Yet here, Intel has decided to eject extra lanes in favor of more cores at a comparable price. I don't get it.

Intel sold the 3820 and 4820 as being part of an HEDT platform, with actual core counts mirroring high end mainstream offerings. That wasn't great, but it gave you a reason to differentiate between an enthusiast platform and the mainstream. Now Intel muddies the water with the bastard child somewhere between the two. Extra processor cores are great, assuming you can use them. If you need extra cores, you're running highly threaded applications. A sizeable chunk of highly threaded applications can utilize GPUs to process data, so more PCI-e benefits them (in a multi-GPU setup).

The only reason I can see the 5820 existing is for VM servers. A couple of extra cores chugging along would be a much needed boost to capacity. Otherwise, Intel has carved out the expensive part of the HEDT platform, in order to offer cores that functionally will be on the die no matter what. I can't see this as a good thing.
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#7
Ferrum Master
by: lilhasselhoffer
Slow clap for Intel....
Yet here, Intel has decided to eject extra lanes in favor of more cores at a comparable price. I don't get it.
I strongly believe all lanes are present there, just disabled for better yield. Maybe some unexpected errata.
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#8
Jizzler
5930K, 5960X on the posted Gigabyte boards:

P1: x16 (x8 when P4 is populated)
P2: x16
P3: x8
P4: x8 (when populated)


Now with the 5820, it turns out to be:

P1: x16 (x8 when P4 is populated)
P2: x8
P3: x4
P4: x8 (when popluated)
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#9
Yellow&Nerdy?
Doesn't seem like a big deal. That means that you can run up to triple card setups at x8/x8/x8, and have 4 lanes for storage and other uses. I'd much rather have the 2 extra cores compared to the i7-4820K than extra PCI-E lanes.
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#10
Dj-ElectriC
Not a deal breaker for dual-card runners. Barely a deal breaker for those who run 3 cards.
I'm totally ok with this, and if this is what needs to be dont to have a 6-core under 450$, than bring it on.
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#11
sumludus
I remember an interview J.J. had on the WAN show a few months back where he talked about how ASUS R&D had put together some designs for an X79 Mini-ITX motherboard, but since he was discussing them openly it could be assumed that it would never see the light of day. However, now with a new X99 chipset to look forward to, and the entry chip having a cut down PCI lane allotment , we might be close to seeing an ITX HEDT. Since we haven't seen anything leaked about it yet, it almost certainly wouldn't be available at launch. But it might be something to keep an eye out for come CES, CeBIT, or even waiting as long as Computex.
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#12
techy1
not deal breaker for me either (I am gonna take mATX anyway).. but CPU wise - is there any difference between i7-5820K and i7-5930K? if not - then it is no brainer - 90% of X99 users should take 5820k unless they are really gonna use triple GPU config. I know that 90% of PC users think something like this: "eventually - I might get triple GPU, so I need my system to be time proof.... more lines you say? here, take my money!" , but lets face it - that "eventually" will never come.
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#13
GhostRyder
So it was just confirmed now...Well this has made this chip all the more interesting because its market is going to have a wild card chip that fits a different niche area the previous X820/k models filled. Its now a "budget" 6 core chip for people wanting more CPU power but only run 1-2 cards (Even though 3 is possible) which will now fill a different need for people.

I think more people would have preferred a 4 core 8 thread variant with the same PCIE lanes as the other top models, however what they essentially did is make an 1150 style chip with 6 cores for those running the standard gaming rig (Or workstation) who do not care.

We will just have to see who bites on this chip, but I would have been more satisfied seeing another Quad core model than this chip. But I am not the one who is targeted for this chip as I want the lanes and the 6 cores (Well I would love the 8 cores but w/e).
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#14
HisDivineOrder
The trade-off for this narrower PCI-Express interface is the fact that you're getting six "Haswell" cores, twelve logical CPUs enabled with HyperThreading, about 12 MB of L3 cache, and a quad-channel DDR4 memory interface, at a price-point not too far off from the Core i7-4790K.
Excepting for the price premium of DDR4 and buying four modules minimum, of course. That's a premium on top of the premium on the motherboard on top of the premium of the hexacore CPU over the mainstream high end CPU.

So really, the price point will be vastly different.
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#15
newtekie1
Semi-Retired Folder
If it truly is a sub-$400 Hex-Core, I'm ok with the slimmed down PCI-E lanes. It is still enough for x8/x8/x8.
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#16
Hilux SSRG
This is utter "High End" garbage from Intel.

How is a upcoming 5820k/X99 combination any better than a current 4790k/Z97?

Throwing out the six/four core argument out the window.

It's going to be slower stock/oc cpu speed, limited to expensive DDR4 only, and more expensive by at least $100.00.

Intel is just killing their HEDT platform sales.
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#17
Dj-ElectriC
^I'm so disagreeing with that my mind hurts.

5820K is a brilliant chip if it is what we think it is. 400$ 6-core, K-CPU (soldered lid). For me, it's better than 4790K in every way possible.

Intel is reviving their HEDT platform with a more affordable 6-core CPU. Yes, DDR4 prices will be high at launch, like every DDR before.

I wan't to see what enthusaist won't upgrade his 4790K Z97 to a 6-core chip 5820K + X99 for about 200$. Sure i would.
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#18
Hilux SSRG
by: Dj-ElectriC
^I'm so disagreeing with that my mind hurts.

5820K is a brilliant chip if it is what we think it is. 400$ 6-core, K-CPU (soldered lid). For me, it's better than 4790K in every way possible.

Intel is reviving their HEDT platform with a more affordable 6-core CPU. Yes, DDR4 prices will be high at launch, like every DDR before.

I wan't to see what enthusaist won't upgrade his 4790K Z97 to a 6-core chip 5820K + X99 for about 200$. Sure i would.
You say HEDT is being revived by Intel, from being what? Expensive? New features being released before the mainstream platforms>?

I don't think it is, at least for gaming enthusiasts. The platform is many things for many users, but speed and overclocking isn't one of them.
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#19
Dj-ElectriC
It's very simple. I want a 6-core overclockable CPU.
I don't want to pay 600$ for one, hence getting one for 400$ is good. "low-end" X99 would not be as expensive as X79 ones were.

You say many things about the platform (witch im preparing for a review atm) without having any experience with this CPU.
It has speed (both CPU and memory) and definitely overclocking. I don't know how you reached those conclusions.
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#20
Hilux SSRG
by: Dj-ElectriC
It's very simple. I want a 6-core overclockable CPU.
I don't want to pay 600$ for one, hence getting one for 400$ is good. "low-end" X99 would not be as expensive as X79 ones were.

You say many things about the platform (witch im preparing for a review atm) without having any experience with this CPU.
It has speed (both CPU and memory) and definitely overclocking. I don't know how you reached those conclusions.
Congrats on purchasing a six-core when it comes out.

But for gaming you may be losing fps by going that route. The last two low end hedt processors 4820k/3820 have been weaker compared to the high end mainstream 4770k/3770k. I don't see Intel reversing the trend especially with the 4790k just arriving recently.
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#21
Dj-ElectriC
Not purchasing anything, i review hardware for a living. :)

4 cores is 4 cores and 6 cores is 6 cores.
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#22
Maban
Why do people insist on arguing about this sort of thing? Some people need HEDT, some don't. Some people need HEDT with 40 lanes. Some need HEDT with 28 or fewer lanes. Some people need ~4790K with a PEX8747. This is exactly why there is such a thing as market segments. To argue over every decision a company makes is rather childish.
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#23
Aquinus
Resident Wat-man
by: Hilux SSRG
Congrats on purchasing a six-core when it comes out.

But for gaming you may be losing fps by going that route. The last two low end hedt processors 4820k/3820 have been weaker compared to the high end mainstream 4770k/3770k. I don't see Intel reversing the trend especially with the 4790k just arriving recently.
Your logic is flawed. The 3820 came out before the 3770k and was a sandy chip. The 4820k is more analogous to the 3770k where the 3820 is better compared against the 2600k or 2700k. Generally speaking the 3820 performed as good or better than it's Sandy equivalent. The only real difference is that it didn't clock as high.

Either way, I still think I would have preferred a quad-core with it's PCI-E root complex intact. Most of the advantage skt2011 has over its mainstream counterparts is it's PCI-E lanes. 6 cores really isn't going to change your gaming experience, even more so when it's shown that as resolutions increase, the amount of CPU power to maintain the same frame rate is less because the GPUs are doing more. So if you're driving 4K displays or surround/eyefinity, I really would imagine that you want those PCI-E lanes. That's me though. I don't plan on divorcing skt2011 any time soon. I really don't think that (other than more cores,) upgrading would get me anything more than just getting a 4930k on the cheap from someone who is upgrading.
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#24
GhostRyder
by: Hilux SSRG
Congrats on purchasing a six-core when it comes out.

But for gaming you may be losing fps by going that route. The last two low end hedt processors 4820k/3820 have been weaker compared to the high end mainstream 4770k/3770k. I don't see Intel reversing the trend especially with the 4790k just arriving recently.
But that is because they were different architectures from the chips that had come out at that time. The 3820 was Sandy-Bridge so even though the 3770K ivy-bridge was out it was on a slightly dated chip architecture and like that the 4820K was Ivy-Bridge while the 4770K was Haswell. The 4820K is also a very good overclocker and was able to beat the 3770K mostly in the range of temps being stable (Plus I saw more chips hitting 4.8Ghz+ than on the 3770K).

The fact is this chip is for people gaming and using a workstation with things like video editing that benefit from the extra cores. It will overclock about as well as Haswell does especially in temps range due to the soldered heatsink and has enough lanes for most peoples setups (2-3 GPU's). Now I personally think the chip is going to be a different niche product this round than it was previously with the changes but its got another area its filling this round.
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#25
Hilux SSRG
by: Aquinus
Your logic is flawed. The 3820 came out before the 3770k and was a sandy chip. The 4820k is more analogous to the 3770k where the 3820 is better compared against the 2600k or 2700k. Generally speaking the 3820 performed as good or better than it's Sandy equivalent. The only real difference is that it didn't clock as high.

Either way, I still think I would have preferred a quad-core with it's PCI-E root complex intact. Most of the advantage skt2011 has over its mainstream counterparts is it's PCI-E lanes. 6 cores really isn't going to change your gaming experience, even more so when it's shown that as resolutions increase, the amount of CPU power to maintain the same frame rate is less because the GPUs are doing more. So if you're driving 4K displays or surround/eyefinity, I really would imagine that you want those PCI-E lanes. That's me though. I don't plan on divorcing skt2011 any time soon. I really don't think that (other than more cores,) upgrading would get me anything more than just getting a 4930k on the cheap from someone who is upgrading.
I agree that hedt's advantage over the mainstream has always been extra pci-e lanes, but Intel creating a niche within the platform is baffling.

Strictly for gaming and overclocking, the 5820k seems like it will be a dud. I'd like to be pleasantly surprised but I see Intel shafting the hedt adopters.
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