PDA

View Full Version : Need a good PCI-E 2.0 graphics card



ilovefilms
04-02-2013, 06:55 PM
I have been gathering parts for a 'super computer' and have come down to the last part and hit a wall. I bought a new Sabertooth 990FX R2.0 motherboard due to its power and dependability and a AMD FX-8350 4.0 GB CPU as the base. Now I am realizing that every good video card I am looking at is a PCI-e 3.0 and the motherboard only has slots for 4 PCI-e 2.0 cards. I am wanting a video card with at least 2GB memory and my intention is some gaming but needs to be able to handle two monitors simultaneously. I keep going through the regular big dealers and amazon in hopes to at least find a decent video card but all I keep finding is PCIe 3.0 cards. Any suggestions? Is there a place where I can find a better selection of PCIe 2.0 cards? Any help is greatly appreciated. My budget on this is $200 to $250 if possible.

zburns
04-03-2013, 09:32 PM
I am thinking that a 3.0 card is backwards compatible with a 2.0 motherboard. So I googled it. Here is the url to go to: https://www.google.com/search?q=can+a+pcie+3.0+card+work+in+a+pcie+2.0+sl ot&rlz=1C1PRFB_enUS475US494&aq=0&oq=can+a+pcie+3.0+card+&aqs=chrome.1.57j0l3j62l2.13546j0&sourceid=chrome&ie=UTF-8

I will look at 3.0 being 'backward compatible' some more tomorrow and probably call EVGA or someone else to confirm that 3.0 will work.

------------------
You will see some comments about a 3.0 card will not run at 3.0 speed in a 2.0 mobo slot, but pretty sure that is not the case. There is no, or very little, speed difference between 2.0 and 3.0 right now !!

Speed increases for 3.0 will come later, several years later.
----------
Yesterday, I stated I would confirm the above comments, which I did today. The overall topic, I think can be confusing, unless one has looked at it multiple times just to get the facts straight.

zburns
04-04-2013, 11:00 AM
Here is the url from a Evga forum that 'absolutely' best explains why you can put a pcie 3.0 card in a pcie 2.0 slot and 'see no difference'. Here is the url: http://www.evga.com/forums/tm.aspx?m=1515736&mpage=1

Note: The url above is from an Evga forum. Click on the above url, then scroll down to the 'seventh' post by 'Lehpron' dated 'Monday, March 26, 2012'. His explanation is excellent and appears to 'cover all the important points'. Particularly, the fact that when using a pcie 2.0 motherboard, you must plug into a 2.0 x 16 pcie slot in order to get maximum speed performance out of a pcie 3.0 card.
------------
My comment: From what I have read on newegg, 2.0 cards are disappearing from the shelves at give away prices. One even reads that 2.0 cards in a pcie x16 slot will perform equally in a 3.0 x 16 slot without any speed loss; technically, this means you can use an old 2.0 pcie video card in a new pcie 3.0 motherboard -- before doing this, I would confirm with the manufacturer that it will work and ask if there are any limitations particularly if you are looking for high frame rates.

It does appear that manufacturers of the new pcie 3.0 cards have taken into account future cross compatibility of both 2.0 motherboards and 2.0 video cards in relation to 3.0 mobos and 3.0 video cards. I assume - one out of several reasons - they have done this is because of the relative high cost of high performance video cards. Said differently, a builder can do a new build with a 3.0 mobo and the respective latest Intel cpu yet continue to use a pcie 2.0 x 16 older video card in the new 3.0 x 16 slot and get the approximately the same speed ( a very small difference in speed hardly recognizable ). Once a 3.0 x 16 card is used, the cpu must support pcie 3.0.

The above compatibility arguments are valid for moderate priced video cards, not the very expensive $ 1000 plus cards that require a very high frequency bandwidth. The reason one can interchange 2.0 x16 and 3.0 x 16 is that the potential bandwidth of the 3.0 x 16 slot is never reached with the current video cards other than the 'expensive' ones (previous sentence).

Closing comment: It is possible a builder would want to re use a 2.0 x 16 slot existing video card in a new build that includes 3.0 x 16 motherboard with an Ivy Bridge cpu (not Sandy Bridge).
Last edited by zburns; Today at 12:41 PM.
-------------
Final message to 'ilovefilms' regards using a pcie-3.0 video card. Seems to be no reason that prevents the use of pcie 3.0 card in a pcie 2.0 x 16 slot; you can expect, essentially, close to the same speed as if the 3.0 card was in a 3.0 x 16 slot. A card that costs apx $ 200 to $ 250 will not have the frequency response requirement that would 'force' the use of a 3.0 x 16 slot; such a card should work fine in a 2.0 x 16 slot.

(Note: notice that I said 'close' to the same speed. When you read about this topic, there is a minor qualification about the two speeds not being exactly the same, but I get the impression it is a minuscule difference or a fractional difference -- not important, etc.. unless it was one of the very expensive cards apx $ 1000 more or less!!)