PCI-E 2.0 / 2.1 what's the diff?

[madcat86]

I posted this under 'a little help' but didn't think about the title. It's a little vague in all honesty.

Anyway, thinking about getting the HD 5870 but read somewhere that it was PCI-E 2.1 - not heard of 2.1 before, there a difference? I got the ASUS crosshair formula III if it helps.

Cheers in advance for any hints and tips

ez

 

[Dauthi]

I guess like PCI-E 1.1 it supports the following gen PCI-E but runs at the current gen speeds.

I.e compatable with PCI-E 3 but runs at PCI-E 2 speeds.

 

[z0mbi3]

There's a difference in power delivered over the slot, I believe.

 

[pastymuncher]

All you need to know here.

 

[StevenRaith]

this is worth a look:
http://docs.google.com/gview?a=v&q=...PCIe_2.1-3.0_update.pdf+pci-e+2.1&hl=en&gl=uk

As far as I can work out, PCI-E 2.1 supports a large propertion of the management and support/troublsheooting systems that will be fully implemented in PCI-E3.0, but it runs at a PCI 2.0 link speed.

It's important to note that [as I pointed out earlier amongst the dozsens of other pages on the 58xx this morning!] Toms Hardware used an Asus Rampage mobo that officlally only supports PCI-E 2.0.

my Mobo [P5Q] is also PCI-2.0 and I wold have no qualms plugging a 58xx in there without hesistation if someone asked me to - I'm that happy that it will work perfectly.

I'm pretty sure PCI-E 2.1 is nothing major to worry about as far as peripherals go; PCI-E 2.0 cards still work in PCI-e 1.0 slots, don't they.

Actually, they do, don't they, just at a lower link speed, isn't it? Must confess, haven't tried it!

 

[madcat86]

Cheers guys, I'll take a ganders at the suggested links when I'm back from work. All sounds quite pleasently hopeful at the moment which is nice having just bought a second 9500 gt and sli bridge for a crossfire mobo.. :s Thought I'd ask the pros first this time.

thanks again

 

[wolvers]

what about 1.0, is it compatible with that?

 

[StevenRaith]

what about 1.0, is it compatible with that?

Wikipedia confirms what I thought; it seems so:

PCIe 2.0 motherboard slots are backward compatible with PCIe v1.x. PCIe 2.0 cards have good backward compatibility, new PCIe 2.0 graphics cards are compatible with PCIe 1.1 motherboards, meaning that they will run on them using the available bandwidth of PCI Express 1.1. Overall, graphic cards or motherboards designed for v 2.0 will be able to work with the other being v 1.1 or v 1.0.

Just not at full whack. As PCI-E 2.1 runs at PCI 2.0 speeds [it seems] then from my logic, that means that it should run in a PCI-1.0 slot -especially if the rumours of it working at 98% speed when CF'd on 2 PCI-Ex8 lanes is taken into account.

Don't quote me on that, though - give it a couple of days and google "5870 on [insert motherboard with P35 chipset here]" as P35s are PCI-E 1.1 IIRC, are they not?

 

[wolvers]

Thanks for digging that info out. I'm fairly confident it won't hurt it too much in my P35.

 

[StevenRaith]

TBH if I were you I'd get a 5850 when they come in, and a good P45 mobo with crossfire support with the £100 you saved.

Better chipset, full PCI-2.0 support, better southbridge [more than likely] and the option to CF up your 5850 in the future for what would probably still be GTX-295 stomping power.

Summat like this:
http://www.overclockers.co.uk/showproduct.php?prodid=MB-281-AS