# pci riser card vs cable (not for mining!)



## FranzSchubert (Feb 24, 2014)

Hello

as a personal side hobby, i have recently started constructing form factor computer cases out of wood (plywood, oak, etc) for my personal, mid-range gaming computer.

i have gone through two versions so far and overall happy with my achievements-my cpus maintain a cooler temp than they ever have with the same amount of fans and i've reduced the overall size of a micro-atx system by 60%!~.

However, i feel i can can reduce the overall size even further if i can figure out a way to change the mounting location of my video card (which happens to be the largest and most cumbersome piece of the puzzle).

recently i discovered the existance of riser cards and cables, which appear to be used for special server PCs and bitcoin mining (what will they think of next!?)

and it seems that google and ebay is flooded with all the wrong information. My local retailers (canadacomptuers) don't stock anything of the like. NCIX and Newegg (canada) have a very limited selection and overall i feel like i can't find the right amount of information on this whole "thing".

i'll leave out MB and GPU listings because they may change in the future, but consider everything new age

ie, pci 16 +, 3.0, etc.

so, my question:

1. is there an impact on performance from using a riser for a single video card

2. aside from the obvious mounting possibilities, is there a difference between CARDS and CABLES

3. am i safe buying the 10-15 dollar stuff from Ebay, or should i stick to some of the server-specific units which seem to have their own capictors and what not (why would they anyway?) (they are in the 30-40 dollar price range)

4. if i do use a CARD, what is the height of the car that i should be looking at. My current video card measured 3.1mm from the card insert itself to the flush side of the fan case. So i assume at a minimum i would need a 4mm "total" height riser? how are their heights measured? i haven't been able to find the right keywords and would appreciate some help in this regard. 

i hope i was clear in my post and if i've left out some things i applogize and let me know how to pinpoint what i'm asking.


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## broken pixel (Feb 24, 2014)

Use powered risers if you do. 
From redit.
[–]aterlumen 2 points 2 years ago
This topic was posted a month or so ago and someone did the math. The extra latency introduced by a riser/extendor was less than the time for a single clock cycle on a decent CPU. If the cable is high quality it has no effect on the bandwidth.


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## The Von Matrices (Feb 24, 2014)

The short answer is that there should be no meaningful impact from using a properly designed extension.

Cable versus card doesn't matter, as long as it can meet the PCIe electrical specification.  PCIe has error correction (128b/130b on PCIe 3.0) that can deal with interference created by moderate cable lengths, but if you make the cable too long it will be prone to generating more errors than can be corrected resulting in system crashes.  The capacitors on high end extensions help to mitigate this issue slightly, allowing longer lengths or lower chance of failure at the same length.

I personally have never seen a straight, rigid, riser card.  All the ones I know of are either right angle rigid cards or straight flexible cables.


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## FranzSchubert (Feb 24, 2014)

thank you for the replies!



The Von Matrices said:


> as long as it can meet the PCIe electrical specification.


 
how would i know this from looking at the product specs?


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## The Von Matrices (Feb 24, 2014)

FranzSchubert said:


> how would i know this from looking at the product specs?



I unfortunately don't know if there is an easy way to tell this.  You basically have to trust the manufacturer that they are honest.  For short cable lengths like you are proposing, you generally don't need extensive shielding so the generic cables should be fine.  If you were looking at 30cm cables, I would begin to worry about the quality of the generic ones.


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## FranzSchubert (Feb 24, 2014)

ohh def this will be under 10 cm (if going by cable), i don't want it too far from the initial socket, just parallel to the board (going away from the cpu) to save the 2" headroom.


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## Vario (Feb 24, 2014)

http://www.techpowerup.com/forums/threads/bento-box.197661/

This guy is doing something similar.  I tried a similar project but I lack the skill to do it well right now so its on hold.


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## beefycarnivore (Feb 27, 2014)

Yeah, I'm looking at the same garbage quality risers / cables as you. I'm probably going to go with cable for now so I can have more placement flexibility, but I've had the exact same concerns as you. I think I'm going to most likely get a powered version, too. I can't find one for less than $20 that I would trust. Looks like that's about the cost for now.


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## Fast-and-Free (Jun 10, 2014)

I started looking into PCI riser cables after I discovered that using it you can make enough room around the graphics card to mount a large CPU heatsink.

I ordered a 15cm ribbon riser cable from ebay and could boot up just fine with it but realized it's not long enough, so ordered a second 15cm one figuring I can connect them together and I won't need more than 30cm
The second one arrived yesterday and what I have unfortunately discovered is that if I connect the card on both risers it will not give me a video feed after windows starts.
If I start in safe mode I see the desktop all right, but if I start normally I get no video feed after the "Windows is starting up" phase. System seems to work fine with either of the cables used independently


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## silkstone (Jun 10, 2014)

The extra connection (when linking two together) probably add too much resistance for a clear signal.


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## CAPSLOCKSTUCK (Jun 10, 2014)

Have you got any pics of your case ?

I am looking for inspiration for a similar project. Recently stripped an old Canadian maple floor and am thinking of using it for a case.


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## Fast-and-Free (Jun 10, 2014)

silkstone said:


> The extra connection (when linking two together) probably add too much resistance for a clear signal.


But what I don't get is, why does it work in BIOS and windows safe mode? I can even boot from an Ubuntu flash drive and go watch youtube without any noticeable video issues 



CAPSLOCKSTUCK said:


> Have you got any pics of your case ?
> 
> I am looking for inspiration for a similar project. Recently stripped an old Canadian maple floor and am thinking of using it for a case.



Sorry, nothing to show at this stage. My videocard is resting on a pile of DVDs next to the case when it's on the cable


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## Shambles1980 (Jun 10, 2014)

just got a 1x - 16x powered riser cable today, i have a media center that only has pci-e x1  and then a add 2 card (all that does is let you add a dvi slot to your on board gpu, but the slot looks exactly like pcie-16, 
any way before i digress. 
the pc would not boot at all with the riser connected to the pci-e x1 slot. just a bunch of error bleeps.
so i ended up having to cut the end of the slot open. this worked though so it now has a hd 6450 in it. 

not to sure what would make the pc not boot just by adding a riser card, the only thing i can imagine is it has a short in it some where. 
At the end of the day it was easier and faster for me to cut open the 1x slot cut 1/2 the cmos battery holder off, then solder some wires to the battery so i could move it out of the way. All in all it was a 20 min job. and has the added bonus of the ports lining up with the slots i have. And still being able to use the pci riser board if i need to use full sized pci cards for some reason. 
just something to think about (possible short on the riser)


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## Fast-and-Free (Jun 28, 2014)

CAPSLOCKSTUCK said:


> Have you got any pics of your case ?
> 
> I am looking for inspiration for a similar project. Recently stripped an old Canadian maple floor and am thinking of using it for a case.



I have completed the first operational build
I will warn you in advance, it's not pretty

I still haven't figured out why 2 cables don't work so I'm running on a single ribbon upside down. It probably does not help cooling performance which is currently not much better than stock (but it's as silent as it gets)


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