Will a PCIe 3.0 slot be usable with an i5-2500K installed

JoeWillie

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Sep 15, 2013
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I just bought a motherboard:

http://pcpartpicker.com/part/asrock-motherboard-z77m

I wanted to go to a smaller board but everything I've read basically says it's not worth upgrading my i5-2500K yet. Problem is my graphics card won't fit in the PCIe 2.0 slot and fit in my case. Will the PCIe 3.0 work with my CPU and just only run at 2.0 bandwith? Hope to get an answer soon since I still have the option to cancel the order since it hasn't shipped. Thanks.

PowerColor PCS+ Radeon HD 7870 MYST. Edition (Tahiti LE) 2GB
 
Hi

If you want a new high power graphics card which physically won't fit in case you need a new case or a physically smaller graphics card

A smaller sized mother board will not help you as location of main PCI-e 16 lane slot will not move much and other similar slots likely to be 8 lane so half speed of main slot

If existing mother board supports PCI-e v2 then v3 graphics card will work but not reach its full potential speed.

What is existing graphics card ?
What will new one be ?
Or have you just purchased one which is too long to fit in case

Regards
Mike Barnes

 

JoeWillie

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Sep 15, 2013
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I am building a scratch case because I am feeling artsy and want the graphics card to fit in the spot closest to the I/O ports and not hanging off the far edge and forcing me to add another rear slot and more length to the case. I didn't realize the PCIe 3.0 vs 2.0 thing until after ordering yesterday just saw 1155 socket. I was just wondering how the PCI 3.0 slot acts if I use my current i5-2500K in the board. Will act as a 2.0 slot or just not work at all. If it dosn't work at all or is slower than a normal 2.0 I need to cancel the order before they ship. Luckily I ordered it after they were closed.

PowerColor PCS+ Radeon HD 7870 MYST. Edition (Tahiti LE) 2GB
 

JoeWillie

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Sep 15, 2013
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Was worried because the manufacturer page http://www.asrock.com/mb/Intel/Z77M/?cat=Specifications says

"- 1 x PCI Express 3.0 x16 slot (PCIE1: x16 mode)
- 1 x PCI Express 2.0 x16 slot (PCIE2: x4 mode)
- 2 x PCI slots
- Supports AMD Quad CrossFireX™ and CrossFireX™

*PCIe Gen3 is supported on 3rd Generation of Intel® Core™ i5 and Core™ i7 CPUs."

It lead me to believe that without a 3rd gen core it would act as a PCIE1. What does that stuff in parenthesis mean, may be a dumb question but can could save me from doing something stupid in the future.
 

JoeWillie

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Well I downloaded the users manual. I know I am dumb for not looking at this to begin with. Answered my own stupid question. I apologize for wasting peoples time. :( Here is the quote from the manual. I still wonder what the stuff in parenthesis means it is awful confusing to me.

"4. Only PCIE1 slot supports Gen 3 speed. To run the PCI Express in
Gen 3 speed, please install an Ivy Bridge CPU. If you install a Sandy
Bridge CPU, the PCI Express will run only at PCI Express Gen 2
speed."