[SOLVED] pcie 3.0 x16 vs pcie 3.0 x4

nawabkhan_u

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Sep 24, 2014
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How a thunderbolt based egpu box which uses just pcie x4 connection which perfoms just 20 percent behind the desktop which uses pcie x16 connection?
In my assumption pcie x4 connection have just 4 pci lane.
pcie x16 connection have 16 pci lane.
so pcie x4 will have 25 percentage perfomance of of pcie x16 connection.
what's wrong with assumption?
 
Solution
How a thunderbolt based egpu box which uses just pcie x4 connection which perfoms just 20 percent behind the desktop which uses pcie x16 connection?
In my assumption pcie x4 connection have just 4 pci lane.
pcie x16 connection have 16 pci lane.
so pcie x4 will have 25 percentage perfomance of of pcie x16 connection.
what's wrong with assumption?
Well the thing is the x4 vs x16 difference is bandwidth. The only cards that can saturate PCIE 3.0 x8 are top tier cards like the 2080Ti. Because of this a lot of less power cards that don’t even use all the bandwidth x8 can supply can get away on x4 with reasonable performance hits.
How a thunderbolt based egpu box which uses just pcie x4 connection which perfoms just 20 percent behind the desktop which uses pcie x16 connection?
In my assumption pcie x4 connection have just 4 pci lane.
pcie x16 connection have 16 pci lane.
so pcie x4 will have 25 percentage perfomance of of pcie x16 connection.
what's wrong with assumption?
Well the thing is the x4 vs x16 difference is bandwidth. The only cards that can saturate PCIE 3.0 x8 are top tier cards like the 2080Ti. Because of this a lot of less power cards that don’t even use all the bandwidth x8 can supply can get away on x4 with reasonable performance hits.
 
Solution