gpudirect storage Will gamers benefit from PCIe Gen 4? - GPUDirect Storage

[Takalot]

Preface:

Spoiler

(My English classes always told me to have an introduction, so that's what this is. It just felt wholly irrelevant to issue at hand, so I put it in a spoiler. Please excuse me if I'm bad at this, I never post to forums.)

 

From my limited perspective, a lot of cool new things have been happening with computers as of late. Things like RTX 3000 Series and Next Generation Consoles seem like they're about to revolutionize gaming as we know it. All this new technology makes it feel like the perfect time to build a pc, and that is exactly what a friend of mine is looking to do. My friend, though, doesn't really know anything about computers, so he came to me.

 

I am eager at the opportunity to help my friend build a pc, but I keep finding myself asking more complex questions than I've ever had to ask before. I wouldn't call myself a PC building noob anymore, but I'm also no veteran. My past builds haven't put a lot of thought into the semantics of SSD types, motherboard features, and other non-surface-level things, primarily because I didn't have to. But with upcoming technologies like GPUDirect Storage, I find myself wanting to know as much as possible so that I can leave my friend with a great PC for years to come.

 

A lot of my questions I've found I can answer with the typical affair of googling things and watching YouTube videos. GPUDirect Storage though, seems really difficult to find information on. It could easily be because there just isn't a lot of information out there, I mean as far as I'm aware, it hasn't even been implemented in 3000 series cards yet. Reviews don't talk about it, cause they can't test it. And any article I can find on pcie gen 4 is months old and doesn't seem to take into account GPUDirect Storage. So I finally decided to come here and make a post asking the question. I am typically a lurker on the internet, and I have never posted on a forum, so I was apprehensive to do so. But I have been having trouble finding answers to my questions, so I think it's about time I started seeking help from others.

 

So with that said...

My Question:

 

If building a PC from scratch with a large budget, is GPUDirect Storage something that should be considered when parting out the system?

If so, will PCIe Gen 4 NVMe see worthwhile performance bumps (or even possibly being required) compared to Gen 3 NVMe or even SATA SSD?

 

---

 

I understand that we may just not have enough information to say right now. I'm not sure if GPUDirect Storage is even available, and I'm fairly certain no games are utilizing it right now. But even if there isn't enough information, do you think it'd be worth getting PCIe Gen 4 now, in a not so literal sense, to future proof a pc when building from scratch.

 

I guess my main concern is that someday PCIe gen 3 will not be fast enough for GPUDirect Storage. I know it will take some time for games to be developed with GPUDirect Storage in mind, but seeing as it's a selling point of PS5 and Xbox Series X, I feel like it will doubtlessly gain relevance in the foreseeable future. With that said, PCIe Gen 4 is much more price prohibitive than Gen 3, and it's hard to tell right now if it's justifiable for a build from the ground up.

[Moonzy]

faster gaming CPU is more important than pcie gen 4, if you ask me

 

it's like like load times will be atrociously slow on gen 3, even if there's direct storage

[Helpful Tech Witch]

13 minutes ago, Moonzy said:

it's like like load times will be atrociously slow on gen 3, even if there's direct storage

Atrociously slow? No. Possibly a large difference compaired to get 4? Possibly.

[Moonzy]

1 minute ago, HelpfulTechWizard said:

Atrociously slow? No. Possibly a large difference compaired to get 4? Possibly.

like NVME vs sata? 6x bandwidth, you dont load 6x as fast, not even 2x

[Helpful Tech Witch]

Just now, Moonzy said:

like NVME vs sata? 6x bandwidth, you dont load 6x as fast, not even 2x

Gen 3 direct storage, where GPU and drive are gen 3 vs gen 4 direct storage, where GPU and drive are gen 4. 

[Moonzy]

1 minute ago, HelpfulTechWizard said:

Gen 3 direct storage, where GPU and drive are gen 3 vs gen 4 direct storage, where GPU and drive are gen 4. 

what makes you think 2x bandwidth will give you significantly better loading times?

i already gave an example on why it probably wont matter

 

though there's really no point discussing, we'll know for sure when it releases

[GhostRoadieBL]

28 minutes ago, Takalot79 said:

I'm not sure if GPUDirect Storage is even available

it's not available yet outside of next gen consoles but it's soon. 

from how it has been described and the idea behind it, drive latency will be more important than raw transfer speed. textures, AI files, environments etc are relatively small files but there's a ton of them and many duplicates when you have rocks, cars, trees etc so loading those files directly to GPU memory will require a lot of throughput but it's more about seeking those files quickly than moving one giant 8GB file at a time. 

PCIe gen4 vs gen3 will likely help with the wider pipeline to send data through but not in the same scale as when SATA turned into NVME. looking at a 2x speed difference IF it can be leveraged efficiently and is wide spread enough to justify developing a whole new programming and loading method which limits the audience of your games to the leading edge of enthusiasts. 

 

What I hope to see is games start being sold on NVME sticks and you can just plug into a front panel slot like the old cartridge days. then it eliminates the need for higher and higher storage amounts and you can finally resell PC games like console disks. 

[Moonzy]

3 minutes ago, GhostRoadieBL said:

What I hope to see is games start being sold on NVME sticks and you can just plug into a front panel slot like the old cartridge days.

software distribution took off because there's low logistics cost to it, i doubt we're going back to hardware based media

 

3 minutes ago, GhostRoadieBL said:

and you can finally resell PC games like console disks. 

game devs:

[Helpful Tech Witch]

1 minute ago, Moonzy said:

what makes you think 2x bandwidth will give you significantly better loading times?

i already gave an example on why it probably wont matter

 

though there's really no point discussing, we'll know for sure when it releases

From my limited understanding, right now, data goes from drive->CPU->GPU for what needs to be loaded into the GPU VRAM. That means that with the 6x bandwidth, the CPU is probably bottlenecking the storage solution. So with  drive->GPU, you bypass the CPU, both removing the possible bottleneck, and bypassing another step, reducing latency.

[Moonzy]

3 minutes ago, HelpfulTechWizard said:

the CPU is probably bottlenecking the storage solution

what makes you think that? we could transfer GB/s files thru the CPU and network

i doubt it'll suddenly be a bottleneck when it comes to feeding the GPU

[GhostRoadieBL]

6 minutes ago, HelpfulTechWizard said:

data goes from drive->CPU->GPU

currently data is 

graphic request at GPU -> CPU -> storage seek -> RAM -> CPU -> GPU VRAM -> GPU 

 

the direct storage seems to be graphic request at GPU -> storage seek -> GPU VRAM -> GPU,

this way the CPU is primarily responsible for character location and movement as well as NPC AI, and maybe some other things like mass data collection for the companies.

this is also massively multi-threaded so drive controllers can get upto the 64+ queue depths where they are more useful.

[Helpful Tech Witch]

8 minutes ago, Moonzy said:

what makes you think that? we could transfer GB/s files thru the CPU and network

i doubt it'll suddenly be a bottleneck when it comes to feeding the GPU

Lol, if it didn't, what makes direct storage so much faster? The latency decreases some, but that  would have a slight increase, and it's being over played a lot more than just a bit.

[Moonzy]

Just now, HelpfulTechWizard said:

what makes direct storage so much faster?

what makes you think it's much faster?

it's just another way to transfer data to the gpu without going through CPU

though, we cant know for sure tbh

no real world example yet, but i would be interested to see if pcie 4.0 makes any significant difference

but bear in mind that majority of people are still on pcie gen 3, so i doubt it'll be a huge impact, even if the dev implements it.

[Helpful Tech Witch]

10 hours ago, Moonzy said:

what makes you think it's much faster?

Nvidia saying so?

Edit: now that I think about it, so did Sony and Microsoft, so.....

[Takalot]

On 9/27/2020 at 7:25 PM, Moonzy said:

majority of people are still on pcie gen 3

I think this is the most important takeaway from this thread.

 

Even if gen 4 is a significant difference, it probably still won't be necessary for gamers. And gen 4 is fairly price prohibitive so it will likely be a long time before widespread adoption. I mean I still know people gaming off of HDDs so..

 

And to further press the point, until it exists it's all just speculation.

 

Thanks for the input guys, I really appreciate it!