Jump to content



Photo

Will my motherboard (Asrock H77M) limit CrossFireX's potential?


  • Please log in to reply
13 replies to this topic

#1 Elliot B.

Elliot B.

    Over 12 years on Neowin

  • Tech Issues Solved: 4
  • Joined: 16-August 01
  • Location: West Midlands, UK
  • OS: Windows 8.1
  • Phone: Samsung Galaxy S4

Posted 24 December 2013 - 01:36

I have a Asrock H77M motherboard and a 7870 XT Tahiti-based video card.

My motherboard supports CrossFireX, so I was going to buy a second Tahiti-based video card.

The website for my motherboard states:
  • 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™
Since the second PCI Express slot is slower than the first slow, will this slow down the second card?

Or - is my motherboard fine to use CrossFireX?

EDIT: The card I have in there covers two slots. I hope it's not covering the second PCI Express slot :/


#2 mattmatik

mattmatik

    formerly soLoredd

  • Joined: 25-November 03
  • Location: California

Posted 24 December 2013 - 01:42

From the picture, looks like your second PCIe slot for a graphics card is at the bottom. So if you put another card in there I believe they will both go to 4x/4x. Not sure what difference this makes, really. My mobo goes to 8x/8x for SLI - think you'd need a pretty beefy mobo to have 2 16x 3.0 slots anyway.



#3 +Phouchg

Phouchg

    Random Oracle

  • Tech Issues Solved: 6
  • Joined: 28-March 11
  • Location: Krikkit
  • OS: VTOS 6.1.7601 x64

Posted 24 December 2013 - 13:41

You can do it, but it will hamper performance. According to Tom's Hardware - about 10-20%.

http://www.tomshardw...w-32164-10.html

 

Also, ensure that there's proper airflow especially for the uppermost card and that you have the necessary power they require to begin with.



#4 OP Elliot B.

Elliot B.

    Over 12 years on Neowin

  • Tech Issues Solved: 4
  • Joined: 16-August 01
  • Location: West Midlands, UK
  • OS: Windows 8.1
  • Phone: Samsung Galaxy S4

Posted 24 December 2013 - 13:47

You can do it, but it will hamper performance. According to Tom's Hardware - about 10-20%.

http://www.tomshardw...w-32164-10.html

 

Also, ensure that there's proper airflow especially for the uppermost card and that you have the necessary power they require to begin with.

That article is almost 3 years old.

 

I wonder if things have improved since.



#5 +PeterUK

PeterUK

    Neowinian Senior

  • Tech Issues Solved: 3
  • Joined: 26-March 07

Posted 24 December 2013 - 16:46

That article is almost 3 years old.

 

I wonder if things have improved since.

 

How old is your Asrock H77M?



#6 OP Elliot B.

Elliot B.

    Over 12 years on Neowin

  • Tech Issues Solved: 4
  • Joined: 16-August 01
  • Location: West Midlands, UK
  • OS: Windows 8.1
  • Phone: Samsung Galaxy S4

Posted 24 December 2013 - 20:40

 

How old is your Asrock H77M?

 

Amazon UK says the motherboard was first available 11 April 2012.



#7 +snaphat (Myles Landwehr)

snaphat (Myles Landwehr)

    Electrical & Computer Engineer

  • Tech Issues Solved: 29
  • Joined: 23-August 05
  • OS: Win/Lin/Bsd/Osx
  • Phone: dumb phone

Posted 24 December 2013 - 20:51

I see no reason why the situation would have changed drastically. The age of his motherboard and the chipset aren't really the problem here. It'd be a driver issue if anything. The industry has probably largely moved on with PCI-E 3.0 and there probably hasn't been a large effort to improve the situation with x16/4x setup.



#8 Snake89

Snake89

    Neowinian

  • Joined: 16-July 04

Posted 24 December 2013 - 21:00

the graphic cards will only running at PCIe 2.0 x4 speeds. kinda making it useless to run crossfire with a 7870.



#9 OP Elliot B.

Elliot B.

    Over 12 years on Neowin

  • Tech Issues Solved: 4
  • Joined: 16-August 01
  • Location: West Midlands, UK
  • OS: Windows 8.1
  • Phone: Samsung Galaxy S4

Posted 24 December 2013 - 21:12

ok cheers, guys :)

 

I'll try and find the cheapest motherboard that supports 2x x16.



#10 +PeterUK

PeterUK

    Neowinian Senior

  • Tech Issues Solved: 3
  • Joined: 26-March 07

Posted 24 December 2013 - 21:24

A newer chipset like H77 vs H57 has not really changed for the PCI-E that it runs off the only reason H77 has PCI-e 3.0 is because thats run off the CPU for one slot instead of running two slots from the CPU and running x8 by x8 without running a x4 slot from the chipset. So not much has changed as motherboard makers are doing this limiting for you to of gotten a better board if you want the most out of CrossFireX setup.



#11 +PeterUK

PeterUK

    Neowinian Senior

  • Tech Issues Solved: 3
  • Joined: 26-March 07

Posted 24 December 2013 - 21:27

I'll try and find the cheapest motherboard that supports 2x x16.

 

With your Core i5-3570K you can only run PCI-e 3.0 x8 by x8.



#12 OP Elliot B.

Elliot B.

    Over 12 years on Neowin

  • Tech Issues Solved: 4
  • Joined: 16-August 01
  • Location: West Midlands, UK
  • OS: Windows 8.1
  • Phone: Samsung Galaxy S4

Posted 24 December 2013 - 21:29


With your Core i5-3570K you can only run PCI-e 3.0 x8 by x8.

Oh. This is all so confusing :( I thought the 3570K was meant to be an excellent CPU?

Would 2x x8 GPUs even be much better than 1x x16 GPU?

#13 +PeterUK

PeterUK

    Neowinian Senior

  • Tech Issues Solved: 3
  • Joined: 26-March 07

Posted 24 December 2013 - 21:36

With the bandwidth PCI-e 3.0 has running a card at x8 is more then enough.



#14 +snaphat (Myles Landwehr)

snaphat (Myles Landwehr)

    Electrical & Computer Engineer

  • Tech Issues Solved: 29
  • Joined: 23-August 05
  • OS: Win/Lin/Bsd/Osx
  • Phone: dumb phone

Posted 24 December 2013 - 21:36

Oh. This is all so confusing :( I thought the 3570K was meant to be an excellent CPU?

Would 2x x8 GPUs even be much better than 1x x16 GPU?

 

I would imagine so. Single cards do not saturate the 16x lanes last I checked. IIRC, there was little difference in using a 16x vs 8x lane in practice for a single card.

 

*Disclaimer: I didn't check the state of recently.

 

EDIT: I just googled briefly, and I'm not seeing anything to indicate otherwise than I just said, so I would surmise that you are good to go with a dual 8x/8x solution.





Click here to login or here to register to remove this ad, it's free!