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.
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.
53 Comments on Intel Core i7-5820K Features Fewer PCI-Express Lanes After All
Monopoly remains monopoly....
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.
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)
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.
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).
So really, the price point will be vastly different.
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 $100.00.
Intel is just killing their HEDT platform sales.
5820K is a brilliant chip if it is what we think it is. 400$ 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$. Sure i would.
I don't think it is, at least for gaming enthusiasts. The platform is many things for many users, but speed and overclocking isn't one of them.
I don't want to pay 600$ 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.
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.
4 cores is 4 cores and 6 cores is 6 cores.
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.
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.
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.