PCI-E 3.0 and current reality?

[qwertymatrix]

As part of getting my CS degree to build my new computer ive found that pci-e 3 has been rolled out and already there are cards being made for this interface i.e. the 7870. Somewhere in the course of looking this up i read that even top of the line cards dont fully utilize the possible bandwidth available on a 16x pci-e 2.x interface/slot. Anyone have more details on this and if this is the case is pci-e 3.0 more or less a useless investment, something akin to buying ssd drives? And then how much of a performance hit will something like the 7870 take being bottlenecked on say a 2.x slot?

 

[PC Beginner]

As part of getting my CS degree to build my new computer ive found that pci-e 3 has been rolled out and already there are cards being made for this interface i.e. the 7870. Somewhere in the course of looking this up i read that even top of the line cards dont fully utilize the possible bandwidth available on a 16x pci-e 2.x interface/slot. Anyone have more details on this and if this is the case is pci-e 3.0 more or less a useless investment, something akin to buying ssd drives? And then how much of a performance hit will something like the 7870 take being bottlenecked on say a 2.x slot?

I would not worry about investing in PCIe 3.0 right now. I have asked question about the 3.0 and I have heard that a Graphics card will not use the 3.0 unless your GPU, CPU, and Motherboard supports. The CPU for 3.0 wont come out until Ivy Bridge comes out, so you wont be able to use PCIe 3.0 yet. Like you said before, graphics cards do not use the full bandwidth of 2.0 slots, so I do not think you 7870 will be bottlenecked.

Here is a review of the 7870 and about its performance if you want to read it.

http://www.pcmag.com/article2/0,2817,2401077,00.asp

 

[Sunius]

There will be virtually no performance loss when comparing PCIe 2.x to PCIe 3.0 with current cards.

 

[Pinhedd]

Rolling out PCIe 3.0 now is a strategic move so that they can deploy it and test it before it actually becomes necessary for performance reasons.

 

[aicom]

As part of getting my CS degree to build my new computer ive found that pci-e 3 has been rolled out and already there are cards being made for this interface i.e. the 7870. Somewhere in the course of looking this up i read that even top of the line cards dont fully utilize the possible bandwidth available on a 16x pci-e 2.x interface/slot. Anyone have more details on this and if this is the case is pci-e 3.0 more or less a useless investment, something akin to buying ssd drives? And then how much of a performance hit will something like the 7870 take being bottlenecked on say a 2.x slot?

Depends on what you're doing. I do some OpenCL coding in my spare time and PCIe bandwidth does make a difference there depending on how you implement your algorithm. Somehow I assume you just want to game with it though.

 

[yumri]

from what i have read the only reason to get a pci-e 3.0 board is if you are doing SLI/crossfire/crossfireX and/or doing openCL / directCompute programming other wise it is a unneeded feature which might be used later in the future IF game makers and video editing program designers decide to go with openCL and/or directCompute more often then it might make a performance boost otherwise PCI-e 2.0 x16 is enough for any card on the market as the Readon 7000 series nor the GeForce 600 series use all the bandwidth allocated to them yet though the Readon 7970 comes close to it but doesnt benefit from having more then just a plain PCI-e 2.0 x16 slot running at the x16 speeds but there is a difference in it from x8 and x16 speeds so getting a board which can do PCI-e 2.0 x16 on the slots you want to use is more important then a PCI-e 3.0 slot as the mechanical doesn't always match up with the electrical thus look at the details on the board's manufacturer site to make sure what you are getting and to have the correct version of PCI-e 2.0 on enough slots for what setup you want to employ.