# PCI-E vs PCI-E 2.0



## tux1308

Will a PCI-E 2.0 card be downwards compatible with a PCI-E motherboard? I have seen specs of one 2.0 card which says that it is but is this applicable to all?


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## HawMan

Check the sticky made by ebackhus for more information on this :




> PCI-Express version 2.0 increases speeds to 32x which is well beyond what most computers can actually use. An important thing to note is that most video cards that are designed for 2.0 will NOT work in 1.0 slots. They will, however, work in 1.1 slots.


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## UncleMacro

Just an additional bit of info: NVIDIA's PCI-Express 2.0 video cards can have compatibility problems with PCI-Express 1.0 motherboards. You can get NVIDIA's to work by flashing the video BIOS if a "fixed" BIOS is available. ATI's PCI-Express 2.0 video cards work fine with PCI-Express 1.0 motherboards. ATI's new video cards start out in 1.0 mode and then only switch to 2.0 if available. As a result, they work fine with 1.0 motherboards.


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## tux1308

How can I determine whether my mob is 1.0 or 1.1? 
I have run that programme to get my computer stats about my PC and all I get for my mob is "P4M890-8237". I have googled this but can't get any luck.


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## tux1308

And this is the card I am looking at getting.

XFX PV-T88P-UDF GeForce 8800GT 16xPCIE 256-bit 256MB DDR3 w/HDTV + 2DVI
[SC-X88GT256]

XFX T88P-UDF , geforce 8800GT , SLi support , Pci-E 2.0 16x , 256mb 256bit DDR3 , support DirectX 10.0 + shader model 4.0 +FP32 HDR + 16x AA ; max resolution 2560x1600 , HDCP Compliant , RoPs : 16 , 57.6Gb/sec memory transfer , 112 stream processors @ 1.5Ghz ( pixel shader engine + vertex pipelines ) , core/memory : 600/1400mhz , 2 x dvi , HDTV tvout .

Is it possible for you to tell me whether this will be compatible? Thanks.

Ive currently been running a 7300 GT. I think thats PCI 1.0?


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## tux1308

Hold the phone! Is PCI-Ex1 = 1.0 and PCI-Ex16 = 2.0?
Sorry for what seem like unbelievable stupid questions.

And I found the specs for my mother board, them being:

Biostar - P4M890-M7 PCI-E

EXPANSION SLOT 2 x PCI Slots
1 x PCI-E x1 Slot
1 x PCI-E x16 Slot


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## tux1308

Been shopping around abit for an ATI card now and I'm looking at the SAPPHIRE HD 3850 512MB GDDR3 PCI-E.

If the 8800GT can work obviously the ATI is the card to take but if the 8800GT, which
of these two would you recommend for better performance?

Thanks so much for the help guys!


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## UncleMacro

> PCI-Ex1 = 1.0 and PCI-Ex16 = 2.0?


No. PCI-Express 1.0 is an older version of PCI-Express. There's 1.0, 1.1, and 2.0. All slots on a PCI-Express 1.0 motherboard including x1 slots and x16 slots are version 1.0. And all slots on a PCI-Express 2.0 motherboard are 2.0 The "x" number of the slot has nothing to do with the version of PCI-Express.

But there are exceptions. It gets more complicated because some motherboards with more than one x16 slot actually have different PCI-Express versions for each x16 slot. One x16 slot can be 1.0 while the other x16 slot is 1.1. Some PCI-Express hardware uses bridge chips which result in some slots using a different PCI-Express version than the main chipset on the motherboard.


Your motherboard uses the P4M890 chipset and it's PCI-Express 1.0a according to these guys. Unfortunately, it _may_ have problems with NVIDIA PCI-Express 2.0 video cards. Some people report problems with 1.0a motherboards and NVIDIA 2.0 video cards and some report that their's work. It doesn't appear to be as clear cut as some motherboard makers have said: ASUS on the subject for a different motherboard. It's hard to know what fraction of people with a given hardware combination have the problem because it's mostly people who have problems who post in the first place. Sadly, this leaves a lot of people in the lurch.

It's hard to guess about the likelihood of having problems with an NVIDIA 2.0 card and your motherboard but I've seen people with this problem and it's a pain to resolve. It involves flashing the video card to a specific video BIOS which makes the card appear to be a PCI-Express 1.0 video card. And that assumes you can find such a BIOS and have a way to flash the video card. It's no big deal if you can find the BIOS and have a machine where you can flash the card. But for most people it's a big pain.


If you're interested in relative speeds of video cards, you should have a look at this table.


If I were in your position... I'd either wait for NVIDIA to sort out its initialization problems with PCI-Express 2.0, or if you can't wait, then I'd limit myself to ATI video cards. Limiting yourself to ATI to avoid this possible problem means you can't get an NVIDIA 8800 GT or 9600 GT both of which are very nice cards. ATI has the 3870 which is about the same speed as the 9600 GT and only a little more expensive. The 3870 is a fair amount slower than an 8800 GT. The 3870 is the fastest ATI card you can get without going to a multi-GPU solution. Your other choice is the ATI 3850 which is probably the best card in its price range. The 3850 is a little slower than a 3870 but it's still pretty quick and is a very good deal for the money.


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## tux1308

Thanks so much for such a detailed answer. Exactly what I needed


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