CrossfireX without a crossfire bridge?

[Val.J]

I`m looking into passively cooled GPUs for a completely silent build. I got the cheapest hd5450, which to my surprise has "crossfireX" supported as per the specifications, but has no crossfire plug on it. Not that i`m doing a crossfire config with two cards like that, but i wondered - can you do crossfire with 2 gpus just with software?

The most powerfull passively cooled GPU that I found was the sapphire hd 7750 ultimate - If it is possible to crossfire two of these, than you can get almost a gaming grade setup which is entirely passively cooled. Any thoughts on that?

[joelthezombie15]

No you cannot. Otherwise why would we still be using crossfire/sli bridges?

[tp95112]

You cant crossfire unless you have the bridge

[Godlygamer23]

I`m looking into passively cooled GPUs for a completely silent build. I got the cheapest hd5450, which to my surprise has "crossfireX" supported as per the specifications, but has no crossfire plug on it. Not that i`m doing a crossfire config with two cards like that, but i wondered - can you do crossfire with 2 gpus just with software?

The most powerfull passively cooled GPU that I found was the sapphire hd 7750 ultimate - If it is possible to crossfire two of these, than you can get almost a gaming grade setup which is entirely passively cooled. Any thoughts on that?

No. You cannot crossfire a 7750 with that. However, older cards can crossfire without a bridge.

Review of it in Crossfire: http://www.tweaktown.com/articles/3121/ati_radeon_hd_5450_512mb_gddr3_video_card_in_crossfire/index.html

[Val.J]

Ok, take this HD7750 for instance : http://www.powercolor.com/Global/products_features.asp?id=413#Specification

Why does it say that it supports CrossfireX when in fact it doesn`t?

[Chevaishr]

the 7750 can indeed crossfire without a crossfire bridge however more powerful cards (i.e. 7770 and up require a bridge )

[ThunderShark]

You need the bridge. Even two-gpu card use a crossfire bridge to connect the gpus, it's just on the pcb

[beefalo]

If you use an AMD apu sustem you can hybrid crossfire with a 7750 which wouldn't require a bridge.

[Val.J]

the 7750 can indeed crossfire without a crossfire bridge however more powerful cards (i.e. 7770 and up require a bridge )

 Are you sure?  Any 7750?

[Chevaishr]

yeah ... i'll go and find one of amd's slides

[Chevaishr]

http://www.profesionalreview.com/wp-content/uploads/2012/10/AMD_CrossfireX_Chart_1618W.jpg

here ... the red means no bridge required......  it also states that if the card feature an external bridge then the bridge must be used 

[Val.J]

http://www.profesionalreview.com/wp-content/uploads/2012/10/AMD_CrossfireX_Chart_1618W.jpg

here ... the red means no bridge required......  it also states that if the card feature an external bridge then the bridge must be used 

So you can match different GPUs in crossfire if i`m reading this chart correctly. For instance a 7970 for the primary gpu and a 7950 for the secondary? Or a 7750 with a 7770 ?

[Godlygamer23]

So you can match different GPUs in crossfire if i`m reading this chart correctly. For instance a 7970 for the primary gpu and a 7950 for the secondary? Or a 7750 with a 7770 ?

Yes. But the faster card will essentially become the slower card. It disables things and down clocks itself to match the slower card.

[Val.J]

Okay, so far so good, you guys are extremely helpful! Just tell me this - can you crossfire more than 2x 7750s ? Because if you can, then in theory you could build a completely silent gaming machine with no moving parts whatsoever (with like 3x passively cooled 7750s)

[Godlygamer23]

can you crossfire more than 2x 7750s ?

No.

[Chevaishr]

Okay, so far so good, you guys are extremely helpful! Just tell me this - can you crossfire more than 2x 7750s ? Because if you can, then in theory you could build a completely silent gaming machine with no moving parts whatsoever (with like 3x passively cooled 7750s)

ok that one i'm not totally sure about 

[Godlygamer23]

Support for my claim: http://www.amd.com/us/products/desktop/graphics/7000/7750/Pages/radeon-7750.aspx#2

Scroll down. You'll see its Crossfire capabilities.