Other Powered pcie riser cable for unpowered graphicscards

deadz0ne

Caliper Novice
Original poster
Mar 16, 2017
22
8
TL;DR: This riser good. Use if card no haz extra power.

This thread is about powered riser cables for graphicscards that have no auxiliary power connector, pulling the full 75W from the PCI slot. The PCIE standard does not specify that 75W can be delivered safely through a riser cable. I.e. using a simple riser to connect a GTX 1050 Ti may work fine, but can void warranty and worst case, damage your components if the riser shorts out due to overheating or whatever. Regular risers have an inherent loss of current due to their design, so in order for 12V to arrive at the graphicscard the current at the PCI slot needs to increase. Most mainboards can handle this, but both the board and the riser were just not designed for this. Longterm reliability (specifically for the case of unpowered graphicscards) has not been tested to my knowledge.
This is where powered risers come in. This specific one I tested is a 30cm riser with a molex connector and capacitors at the female end. This allows you to feed in power directly from your powersupply circumventing the load at the PCI slot entirely. The capacitors are there to filter current overflow. This happens when the GPU changes from high load to low load rapidly. Figuratively speaking, the current still has high momentum going through the wires and if not absorbed by a capacitor will go directly into the card (this problem really only exists with long wires). OK, too much info here, back to topic!

There seems to be a lack of information on this topic so I decided to do some of my own testing.

First tests with this riser: https://www.moddiy.com/products/PCI%2dExpress-PCI%2dE-16X-Riser-Ribbon-Extender-Cable-w{47}Molex-%2b-Solid-Capacitor-(30cm).html


Current setup:
Intel Pentium G4560
Noctua NH-L9i
GSkill DDR4 2133 8GB
MSI B250I Pro
ADATA Ultimate SU800 M.2 256GB
Streacom ST-NANO160 160W
MSI GTX 1050 Ti 4G OC

From my tests I have concluded that the riser does not impact performance at all. It seems to be pretty reliable, so far. Good choice for people using cards with no external power connector (like GTX 1050 Ti). For 18€ (not including shipping) it's a great deal!

Here some early benchmark results:
3DMark Time Spy 1080p without riser: 2354pts
With riser: 2355pts
Witcher 3 1080p w/o riser: 40fps avg
W/ riser: 40fps avg
I did have to set the PCI mode to 2.0. Auto or 3.0 didn't work properly (crashes and terrible performance).
Length wise the riser seems ok but will have to test in the case.

Will keep you guys posted if anything changes. Be cool if some of you could also post results.
 

aquelito

King of Cable Management
Piccolo PC
Feb 16, 2016
932
1,078
I have this one from Vary Tech (website currently down) which works in PCI mode 3.0 :

Shielded and very flexible.