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View Full Version : pci-e 16x 2.0/3.0 differences



exgearuser
03-21-2013, 12:59 PM
I've been looking over a few things and am wondering if upgrading to an Ivy bridge CPU would be worth it for me. I want to set up an EVGA 670 ftw sli setup and I have this mobo http://www.newegg.com/Product/Product.aspx?Item=N82E16813130611 .
I'm not quite sure of the pci- e limits in 2.0 or 3.0 mode (sandy bridge I have now compared to a new Ivy bridge upgrade) According to a few places I've found http://www.reddit.com/r/gamingpc/comments/179tvn/3_monitor_surround_vs_ips_1440p_27_repost_from/ and http://i.imgur.com/15Rbq.png extreme resolutions might actually benefit from a swap to pci-e 3.0. Anyone have any thoughts on this? Honestly I dont even know if this particular board can DO pci-e 16x on both rails, and if its worth upgrading my 2500k to something else.

Cpt.Teacup
03-21-2013, 01:34 PM
PCI-E 2.0 has a bandwidth of 500MB/s per lane, 3.0 is almost double that. With 2-way SLI you're most likely using x8/x8 mode so with 2.0 your bandwidth is 4GB/s and with 3.0 it's just under 8GB/s.

Someone else can post the cards data transfer rate.

Sneaky
03-21-2013, 04:38 PM
That MSI MB (the one you have) will do 3.0 Bandwidth on the PCI-E lanes but not with your 2500K.
There have been lots of tests on the interweb that show you really won't see benefits of PCI-E 3.0
until you go tri or quad SLI. That being said, with our high res 120hz monitors you might see a slight improvement. ;)

EniGmA1987
03-21-2013, 07:02 PM
If you are running a single GPU then you wont see a benefit from PCI-E 3.0 for another generation or two of graphics cards.

winterhell
03-22-2013, 03:42 AM
Actually PCI-E 2.0 is very underused in single GPU configurations. Even during loading times, it takes just a split second to transfer all the textures and vertex buffers into VRam. Its mostly used when you run out of memory so the card has to transfer the same couple of textures over and over again at least once per frame, but you don't want to go there.

Shadman
03-22-2013, 04:42 AM
Good to have breathing room for later, or dual-GPU on one card. And OCD.

HyperMatrix
03-22-2013, 06:32 AM
I had no PCIE lane limitations with 8x/8x on pcie 2.0 with my 2600k and 2x gtx 680's. Going to 2 GTX 690's, and it was just death. So for 2-card SLI I'd say it's fine. Anything above that, you will *need* to upgrade. That's the reason I upgraded from my 5ghz 2600k to a 4.6ghz 3770k (until I bought my 5ghz 3770k very recently). For the pcie 3.0. 8x pcie 3.0 = 16x pcie 2.0. So that's handy. And honestly I'd say don't worry about PLX. It has a 100ns latency. Or so I've been told. Which is really nothing.

exgearuser
03-22-2013, 08:57 AM
Thanks guys, I think I've been reading too much...everything from how pcie 3.0 8x is equal to pcie 2.0 16x to sli bandwidth issues to cpu bottlenecking (not blaming you on that one Hyper) I think Ill stick with my original upgrade path when I first built this pc, stick with my 670 sli plan and see how it goes...I mean I just got the damn screen I should play around more before I assume what I'll need for my rig to feed it :P