AMD or Intel for GeForce RTX 3080 Benchmarking: Is PCIe 4.0 a Factor?

Puiu

Posts: 4,076   +2,627
A few direct comparisons wouldn't hurt since we're talking about early drivers which may or may not be properly optimised for both platforms, but using these results we can infer a lot of the data.
 

Achaios

Posts: 52   +151
AMD is the future.

My next mobo/CPU upgrade will be AMD and ASUS. I have never owned an AMD CPU before.

Intel would just sell us monocore 130nm CPU's sans HT if they could get away with it. Intel are admirers of stagnation and obsolescent tech and an enemy of progress not to mention the fact that they are gonna be on 14nm for many years to come.

Good riddance.
 

Irata

Posts: 876   +1,245
TechSpot Elite
If you wanted to compare the effect of PCIe 3 vs 4, would it not have been more straight forward to make the comparison between B450 and X570 ?

Other than that, great review and I'm looking forward to the first next gen reviews.

Being on B450 but only interested in mid range GPU , I am curious if PCIe 4 makes a difference with next gen GPU and if so in which tier(s).
 
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Shadowboxer

Posts: 933   +553
I’d say pick the CPU that benches the fastest. If PCIe4 makes cards faster on Ryzen the faster go with Ryzen, if it doesn’t and Intel is still faster than use Intel.

Neither is a typical scenario, I don’t think that many gamers are buying either CPU when it comes to the i9 or R9, instead a 3600 or a maybe a 10600K is a best representation of what users may buy with a new GPU when building a new rig.

But looking at the GPUs and the fact that we aren’t likely to see any bottlenecks I don’t think it matters that much. AMD fanboys will be filled with glee to see Ryzen on a gaming GPU test bench so you may aswell throw them a bone when the CPU performance doesn’t really matter.

But I do think it’s important that if PCIe4 doesn’t affect performance that you let users know. Motherboard manufacturers and AMD seem to be very keen to promote PCIe4 but in reality most users wouldn’t be able to tell the difference over PCIe3. And I have no doubt that PCIe4 will be written all over the GPU boxes even if it has no benefit.

It also may worth bearing in mind that Ryzen 3 is apparently due to drop within the next few months and if it performs faster it will do Ryzen a dis-service as over the next year when people are reading the reviews in a few months (which is very possible, not everyone buys GPUs on release). I can definitely see confusion between Ryzen 3xxx and Zen 3 occurring. We wouldn’t want to lead users to buying Intel because it’s faster than Ryzen 3xxx when Ryzen 4xxx stuff is faster (if it’s faster).
 

Shadowboxer

Posts: 933   +553
Here's another thought: If 16 PCIe 3 lanes turn out to not be a bottleneck, wouldn't it be possible to run the CPU on PCIe 4 x8 (same bandwidth) and have eight lanes left over for nVME, add in cards.... ?

I think there are B550 boards that support this.
I have a 6 year old Z97 board with no M2. And I use an adapter on the 3rd slot on the board for an M2 drive. I was convinced this would reduce my lanes to 8 but it doesn’t. GPUz reports 16 lanes still. I didn’t bother checking any further but I don’t think you always lose 8 lanes by using an adapter, it depends on the mobo maybe.

Also, prior to purchasing the adapter I researched and found that 8x PCIe3 doesn’t slow down your GPU, it offers enough bandwidth for modern current cards. Which is why I’m personally skeptical that PCIe4 will yield an advantage for the new upcoming graphics cards, I guess we’ll find out when TechSpot test it and publish the results.

I think PCIe4 is more useful for OEM marketing departments than actual users at this point
 
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ZackL04

Posts: 687   +454
I know your just creating this article for reader inclusion and to bring up a good topic to think on.

But the obvious answer is: Ask Nvidia

They’ll know which platform performs best with their newest hardware at all resolutions.

They are the leaders in the GPU tech and have been for a long time. They know what their doing and how to get the most out of their products.
 
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neeyik

Posts: 1,345   +1,444
Staff member
I have a 6 year old Z97 board with no M2. And I use an adapter on the 3rd slot on the board for an M2 drive. I was convinced this would reduce my lanes to 8 but it doesn’t. GPUz reports 16 lanes still.
That chipset has 8 PCIe 2.0 lanes, and the CPU will have 16 of the same. The CPU only supports x16, x8+x8, and x8+x4+x4 configurations, so if you're using an add-in x16 graphics card as well, it will be configured in one of the two ways:

  • 16 CPU lanes for GPU + 8 chipset lanes for adapter
  • 8 CPU lanes for GPU + 8 chipset lanes for adapter

The Z97 chipset doesn't support the combination of lanes between itself and the CPU (it's a point to point interface, after all) so GPUz, the adapter, or the chipset is incorrectly reporting the PCIe information configuration.
 
How is this even a thing? and why ignore the fact that so many AMD users don't have a 3950x much less a 550 or 570 board to use it on? A person could be running a 3950x on an x470 board where pci-e 4 is irrelevant. Are you going to label every graph as pci-e 4 so they know?

If you run a 3950x and it turns out its bottle-necking (same for an intel CPU), you're doing your viewers a disservice. The reality also might be that faster GPUs result in a wider performance delta between the 10900k and 3950x.

A poll I see as relevant is asking what systems they are using in case you would rather tailor your tests to the majority. This noise is premature. The article should be about what the findings are when the cards actually launch.
 

John Galt

Posts: 19   +4
To avoid picking based on a one-trick pony CPU, they should pick a budget point ($500, $750, $1000, or any random number that gets two competing chips).
 

Shadowboxer

Posts: 933   +553
That chipset has 8 PCIe 2.0 lanes, and the CPU will have 16 of the same. The CPU only supports x16, x8+x8, and x8+x4+x4 configurations, so if you're using an add-in x16 graphics card as well, it will be configured in one of the two ways:

  • 16 CPU lanes for GPU + 8 chipset lanes for adapter
  • 8 CPU lanes for GPU + 8 chipset lanes for adapter

The Z97 chipset doesn't support the combination of lanes between itself and the CPU (it's a point to point interface, after all) so GPUz, the adapter, or the chipset is incorrectly reporting the PCIe information configuration.
That’s what I assumed before I purchased the adapter and then I discovered it says something about my board having extra lanes connected to the CPU PCH. Which I didn’t know was a thing available on Z97 but here it is;


So I don’t think it is being reported incorrectly.
 

neeyik

Posts: 1,345   +1,444
Staff member
That’s what I assumed before I purchased the adapter and then I discovered it says something about my board having extra lanes connected to the CPU PCH. Which I didn’t know was a thing available on Z97 but here it is;


So I don’t think it is being reported incorrectly.
Let me quote the relevant section for that particular motherboard:
The PCI-Express layout is aimed at (most common) 2-way SLI and CrossFire users with its two, red PCI-Express x16 slots providing 1x16 or 2x8 from the CPU. If you're using more GPUs, wait for our Computex announcements!

Three open-ended PCI-Express x1 slots, a PCI-Express x16 (x4 electrically) and the M.2 (PCI-E x2) slot are all connected to the Z97 PCH. Note that due to the limitation in number of available Z97 PCI-Express lanes, these PCI-Express lanes are shared.
So the two red PCIe slots are connected to the CPU and share those 16 lanes. The three PCIe x1 slots, along with the black PCIe x16 slot, and the M.2 PCIe x2 slot share the 8 lanes in the Z97 chipset.

The only way to get more than 8 additional PCIe lanes is to have an extra controller chip on the motherboard. What brand/model is yours?
 

Shadowboxer

Posts: 933   +553
Let me quote the relevant section for that particular motherboard:


So the two red PCIe slots are connected to the CPU and share those 16 lanes. The three PCIe x1 slots, along with the black PCIe x16 slot, and the M.2 PCIe x2 slot share the 8 lanes in the Z97 chipset.

The only way to get more than 8 additional PCIe lanes is to have an extra controller chip on the motherboard. What brand/model is yours?
It’s an Asus ROG Hero VII. The Asus website states it has a PCH, I linked it above.

“Three open-ended PCI-Express x1 slots, a PCI-Express x16 (x4 electrically) and the M.2 (PCI-E x2) slot are all connected to the Z97 PCH”.

SoI guess Asus added a PCH to accommodate the M2 and other slots on the board. Although the M2 slot doesn’t work on my board and users on the OC3D and ROG forums who have the same board seem to all say theirs don’t either. It’s also only 2 lanes, if you use an adapter the grey slot gives you four.

However, I don’t know any other way of verifying how many lanes my GPU is getting aside from in GPUz. There was certainly no performance hit when I started using that drive.
 

neeyik

Posts: 1,345   +1,444
Staff member
It’s an Asus ROG Hero VII. The Asus website states it has a PCH, I linked it above.

“Three open-ended PCI-Express x1 slots, a PCI-Express x16 (x4 electrically) and the M.2 (PCI-E x2) slot are all connected to the Z97 PCH”.
The Z97 PCH is the chipset; it's not an additional chip. From your link:
The default setting is Auto Mode, which automatically assigns the PCI-Express lanes, meaning if you install a PCI-Express x4 device into the bottom slot, the system will automatically detect and disable the x1 slots and M.2 slot.
Three x1 slots, one x4 slot, and one M.2 x2 slot comes to 9 lanes in total - hence why if you put something into the black x16 slot that uses at least 4 lanes, the others get disabled.
 

Squid Surprise

Posts: 3,461   +2,358
Because the workload would then be unachievable, within the timeframes of publishing deadlines, costs, food, sleep, life, etc.
Then you need to hire more staff or increase your budget... because this is probably the single most important thing your site does.

In order to accurately assess these new video cards - as well as AMD’s which we must assume will be released fairly soon - the user needs to know which platform to use with them.

Not having 2 systems is simply unacceptable.
 

Shadowboxer

Posts: 933   +553
The Z97 PCH is the chipset; it's not an additional chip. From your link:

Three x1 slots, one x4 slot, and one M.2 x2 slot comes to 9 lanes in total - hence why if you put something into the black x16 slot that uses at least 4 lanes, the others get disabled.
Well the article makes it clear that the PCH lanes are shared. Not that these are shared between your CPU lanes and PCH lanes, which is what I assumed but I now think was wrong. Also the ROG forums all seem to say that these lanes are seperate. It’s also the same way Z170 boards work, they just have a PCH to get the extra lanes but they get a lot more and faster.

I even found a TechSpot article confirming that Z97 can have extra lanes;


I know what I can do to test it, I have an old GTX970 lying around and so does my mate, il ask him if I can borrow it and if I can get them running in SLI with my M2 plugged in then I know that I still have 16 lanes for graphics.
 
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