PCIe 1.0 vs. PCIe 2.0 - Noticeable Differences

[BlockheadBrown]

Just out of curiosity, would I see noticeable differences between a motherboard that only supports PCIe 1.0 (16x) vs. PCIe 2.0 (16x)? What card would max out the bandwidth supported in PCIe 1.0?

Thanks in advance.

 

[Meaker10]

Single card? You might see a tiny impact on a highly overclocked 7970... a couple of percent.

 

[Necc]

srsly? no.

Upgraded from my HTCP from asus P5B (pci-e 1.1) to P5Q (pci-e 2.0) same processor. no noticible fps gain on sport games.

 

[RavenSEAL]

srsly? no.

Upgraded from my HTCP from asus P5B (pci-e 1.1) to P5Q (pci-e 2.0) same processor. no noticible fps gain on sport games.

I think I found your problem.

 

[Meaker10]

Not really since it's true for any game.

You only see advantages in optimus and multi card rigs, and only then to a certain degree.

 

[evilspoons]

Do you guys even read Anandtech?

Scroll down to "PCIe 3.0 Bandwidth Comparison": http://www.anandtech.com/show/5458/the-radeon-hd-7970-reprise-pcie-bandwidth-overclocking-and-msaa

Note that, more or less, a PCIe 3.0 x4 slot has the same bandwidth as a PCIe 2.0 x8 slot and a PCIe 1.0 x16 slot. There are measurable but not super huge drops in performance on the 7970 at the PCIe 3.0 x4 level vs PCIe 3.0 x16 - 8% on Shogun, 18% on the Dirt 3 minimum frame rate. PCIe 2.0 x16 and PCIe 3.0 x16 are much closer, implying that PCIe 1.0 would be a minor restriction but 2.0 vs 3.0 wouldn't matter at all.

And Meaker10: the charts clearly show that different games are influenced differently by lack of bandwidth. Some don't care at all and others see noticeable drops when artificially limiting to x2 (see Batman vs Shogun on the second chart.)

 

[MrK6]

As evilspoons pointed out, it depends on the card. The 7970, 6990, and GTX 590 are going to be the most affected since they have to pump the most data through a single 16x slot.

Therefore, OP, it'd help to know what your rig specs are, especially what graphics card you are using, in order to properly answer your question.

 

[BlockheadBrown]

I've had to downgrade my PC gaming rig recently due to finances. I sold off my P67 mobo, my i5-2500K proc and returned my GeForce 560 Ti 448. I just put the leftover HD in the HTPC I had and got a decent graphics card (still waiting for it). After all is said and done, I'm looking at the following:

Radeon 6870 1GB
8GB DDR2 RAM
Intel e5200
7200rpm HDs

A few things:
1.) I know my biggest limiting factors are going to be the processor, DDR2 and HDs.
2.) I am trying very hard not to spend more money on this project. I am mainly a PC gamer, but I've had to cut back due to financial concerns. Upgrading mobo, proc, HDs, etc. work against the goal of selling off/returning my hardware for cash.
3.) If gaming gets to be to difficult with the above setup, I may just sell off the video card and large HD I have and ... ::shudder:: ... just use consoles for gaming.

I'm not trying to cry poor or anything. I'm just trying to do the best I can with what I have at minimal cost. Whenever the video card comes in, I'll do some tests. As mentioned in 3, if it's not up to par, then it's off to consoles I go. Frankly, it's still tempting to sell off the large HD, but I'm fighting the urge to do so. I have a number of games on PC and while I don't foresee installing all of them right away, I like having the option to do so. On the other hand, if I sell it now and just use the 500GB HD I have as my main HD, that's more money that could help things out for the financial situation. :onders::

 

[RavenSEAL]

You'll be fine with an HD6870 at PCIe 1.0 x16, might lose a frame or two off the top.

 

[Meaker10]

Do you guys even read Anandtech?

Scroll down to "PCIe 3.0 Bandwidth Comparison": http://www.anandtech.com/show/5458/the-radeon-hd-7970-reprise-pcie-bandwidth-overclocking-and-msaa

Note that, more or less, a PCIe 3.0 x4 slot has the same bandwidth as a PCIe 2.0 x8 slot and a PCIe 1.0 x16 slot. There are measurable but not super huge drops in performance on the 7970 at the PCIe 3.0 x4 level vs PCIe 3.0 x16 - 8% on Shogun, 18% on the Dirt 3 minimum frame rate. PCIe 2.0 x16 and PCIe 3.0 x16 are much closer, implying that PCIe 1.0 would be a minor restriction but 2.0 vs 3.0 wouldn't matter at all.

And Meaker10: the charts clearly show that different games are influenced differently by lack of bandwidth. Some don't care at all and others see noticeable drops when artificially limiting to x2 (see Batman vs Shogun on the second chart.)

Let me get this straight, taking the highest possible single core card in existance and talking about a Gen1 mobo, you really think he was going for 7970. Also notice the still more than playable frame rates.

It's obvious someone talking about that kind of mobo was going for a much lower card.

The 6850 will show a much smaller drop.

Also lol at 18% worst case on MINIMUM frame rates. I'll cry for all of those 7970 users on gen1 mobos if you like. Plus we dont know how long those were sustained or if they affected gameplay at all.

 

[BlockheadBrown]

Thanks to everyone for their contributions. Best wishes!

 

[evilspoons]

Let me get this straight, taking the highest possible single core card in existance and talking about a Gen1 mobo, you really think he was going for 7970. Also notice the still more than playable frame rates.

It's obvious someone talking about that kind of mobo was going for a much lower card.

The 6850 will show a much smaller drop.

Also lol at 18% worst case on MINIMUM frame rates. I'll cry for all of those 7970 users on gen1 mobos if you like. Plus we dont know how long those were sustained or if they affected gameplay at all.

- Minimum frame rate influences playability the most.
- You specifically mentioned the 7970 in your first post anyway.
- "More than playable" is not relevant so much as there is a noticeable drop, which is what the OP's question was.
- Relax!

 

[Meaker10]

As DiRT3 is one of our higher performing games in the first place the real world difference is not going to be that great – it’s still well above 60fps at all times – but it’s clear that in the wrong situation only having 4GB/sec of PCIe bandwidth can bottleneck a 7970.

I answered his question the best way. I just seem to be dealing with a lot of pedantic people on forums today. There are edge cases (which in this case dont matter because they are likely linked to the high frame nature of the game, if they were running at lower frame rates, the PCI-e bus would not be as saturated and the frame rates would be less effected).

So you pedantry does not even apply.