Do I not get PCI 3 if I put a SB chip in a Z77 board?

Cythx · 19 Apr 2012 at 13:11

PCI 3 is looking to be real important for multi-monitor multi-GPU setups, so if a SB chip will block me from using the PCI 3 functionality on my Z77 board, I will deff. not be buying SB.

Thanks.

opethdisciple · 19 Apr 2012 at 13:12

Do I not get PCI 3 if I put a SB chip in a Z77 board?

Nope.

paradisiac · 19 Apr 2012 at 13:13

nope, IB only.

Cythx · 19 Apr 2012 at 13:14

K well I'm going IB then.

paradisiac · 19 Apr 2012 at 13:16

do you NEED PCI-E 3.0 ? i read there is very little gains if any at the moment.

Cythx · 19 Apr 2012 at 13:18

PCI 3 is not really important for single monitor single GPU setups.

PCI 3 is incredibly important for multi monitor multi GPU setups. I have a U2711 and I'm planning on expanding, when I do, I will need to go from a single 680 to 680 SLI. When this happens, PCI 2 would be a huge bottleneck.

paradigm · 19 Apr 2012 at 13:49

Cythx said:
PCI 3 is not really important for single monitor single GPU setups.

PCI 3 is incredibly important for multi monitor multi GPU setups. I have a U2711 and I'm planning on expanding, when I do, I will need to go from a single 680 to 680 SLI. When this happens, PCI 2 would be a huge bottleneck.

A huge bottleneck? Find me a GPU that gets "hugely bottlenecked" by an 8x PCIe 2.0 slot?

I guarantee that you won't.

Cythx · 19 Apr 2012 at 16:25

paradigm said:
A huge bottleneck? Find me a GPU that gets "hugely bottlenecked" by an 8x PCIe 2.0 slot?

I guarantee that you won't.

A single GPU on a single monitor resolution? No, there isn't one that will get bottlenecked under such circumstances. However, I never said there was such a case.

I think you need to re-read what I said, and more carefully too.

I was talking about a bottleneck in a setup including 2 high end GPUs like the 680 with multiple monitors, for example 3 1080p screens.

Setups like those is where you'll see PCI 2 bottlenecking, according to several people who have multi GPU multi monitor setups and have tested both PCI 2 and PCI 3.

Rusty0611 · 19 Apr 2012 at 16:31

I think the issue was more to do with the term 'huge' bottleneck. Which you clearly won't have with x8 PCIe 2.0.

Way to go on the ultra defensive though

pzr vr6 · 19 Apr 2012 at 16:46

1 7970 at 5760 x 1200 would that be a bottleneck on pcie2?

paradisiac · 19 Apr 2012 at 16:53

i never read HUGE bottlenecks between PCI-e 2.0 and PCI-e 3.0, bottlenecks maybe, but not HUGE.

arekgreenman888 · 19 Apr 2012 at 16:55

So pcie 3 will only kick in if IB is installed and not my SB k2500i?

paradisiac · 19 Apr 2012 at 17:02

arekgreenman888 said:
So pcie 3 will only kick in if IB is installed and not my SB k2500i?

correct, the SB i5 2500k will only work on PCI-e 2.0

panyan · 19 Apr 2012 at 17:03

arekgreenman888 said:
So pcie 3 will only kick in if IB is installed and not my SB k2500i?

correct

arekgreenman888 · 19 Apr 2012 at 17:07

panyan said:
correct

That is stupid. Why is cpu limiting gpu bandwitch? k2500i can handle pcie 3 speeds. Why this limit?

I am worried my amd 7850 2gb will be limited to pcie 2 speeds on my Gigabyte Z77X-UD3H board. Is that right? Until i put in IB cpu in things will stay at pcie 2 speeds?

Ollie1132 · 19 Apr 2012 at 17:08

Its because the cpu chips have the PCI controllers and SB chips only have PCI 2 controllers basically. Not that you really need PCI 3 anyway... PCI 2 8x is more than enough for anything really...

paradisiac · 19 Apr 2012 at 17:09

arekgreenman888 said:
That is stupid. Why is cpu limiting gpu bandwitch? k2500i can handle pcie 3 speeds. Why this limit?

I am worried my amd 7850 2gb will be limited to pcie 2 speeds on my Gigabyte Z77X-UD3H board. Is that right? Until i put in IB cpu in things will stay at pcie 2 speeds?

the difference in speed is negligable. the reason SB dont do it is the chip doesnt support it, nothing to do with power, its a different chip.
im sure a lot if Q**** skt 775 chips have the power to run PCI-e 3.0, but it still doesnt mean they can.

scrlk · 19 Apr 2012 at 17:22

Intel moved the PCI-E lanes from the Northbridge/FSB directly on to the chip on Lynnfield (P55 platform) and onwards.

Reasons?

Cheaper
Faster

because they removed the need for the Northbridge.

EDIT: On the other hand, X58 still used an IOH (a tarted up NB if you would like to put it that way) which means if you had a new IOH you could probably have PCI-E 3.0 support, but then the QPI is the limiting factor.

Cythx · 19 Apr 2012 at 19:19

Rusty0611 said:
I think the issue was more to do with the term 'huge' bottleneck. Which you clearly won't have with x8 PCIe 2.0.

Way to go on the ultra defensive though

After looking at the graphs below, can you please show me where it is so clear to you that you clearly won't have a huge bottleneck?

I would really like any sources that bench SLI 680/7970 with multi monitor setups such as the ones listed below.

This is 'huge'. If you want more information, talk to Vega, these are his results.

The bars you will want to be looking at are the 2nd and 4th set, as they are the multi monitor setups.

This is also 'huge'. If you want to contact the person who made the graph, ask me and I'll find out where I got the graph.

beejjacobs · 19 Apr 2012 at 19:28

the first one bare in mind if 4-way SLI, which is quite an extreme case.

I was talking about a bottleneck in a setup including 2 high end GPUs like the 680 with multiple monitors, for example 3 1080p screens.

That is far less than what Vega i running, and in the second graph I wouldn't say the difference is huge.