eDP cable compatiblity query

[Haggisman]

I managed to snag a cheap 2nd hand Acer Predator laptop (PH315-53) a few months ago, the spec is fine, except for the screen being only 1080p (@144hz), so I've installed a 1440p/165hz screen.

It works fine, but in the OS it's limited to 60hz regardless of resolution. On further investigation, it looks like the eDP cable is only 2-lane, whereas I need a 4-lane one (the EDID data from the monitor does correctly show as supporting 2560x1440/165hz).

In theory not an issue - this model was also available with a 240hz 1080p screen, which also requires a 4-lane cable, so there is a compatible part for it, however this is where my research is failing me. AI is suggesting that even though the 4-lane cable exists, it will be wired specifically for a FHD signal and so won't allow for the higher refresh rate at QHD.

While I'm not an expert, this sounds a bit strange to me, surely 2-lanes vs 4 is just a matter of bandwidth rather than specific wiring?

Any advice from someone a bit more knowledgeable would be very welcome!

 

[Purgatory]

@Haggisman

Yes if you have the slower 2 lane just get the 4 lane one and make sure same pin count. The only limiting thing could be the motherboard end that is not fully wired for 4 lanes but maybe you can check the motherboard connector end looks fully populated with pins and has pcb traces showing enough connections.

Honestly most of these cables are cheap enough to try them and see also when you do that to install any driver for the new screen so windows recognises it correctly if it doesn't automatically detect it correctly. Is yours the 30 pin or 40 pin connectors on the motherboard and screen?

 

[Haggisman]

@Haggisman

Yes if you have the slower 2 lane just get the 4 lane one and make sure same pin count. The only limiting thing could be the motherboard end that is not fully wired for 4 lanes but maybe you can check the motherboard connector end looks fully populated with pins and has pcb traces showing enough connections.

Honestly most of these cables are cheap enough to try them and see also when you do that to install any driver for the new screen so windows recognises it correctly if it doesn't automatically detect it correctly. Is yours the 30 pin or 40 pin connectors on the motherboard and screen?

It's 40 pin on both end, so physically should fit, as you say, it's just if the motherboard isn't fully wired up, but since it came with a 240hz option, I would be surprised if that were the case, since I would have thought it would be easier to have a single motherboard for both options and just fit the appropriate screen.

The proper 240hz cable is £40, but I found one on AliExpress with what appears to be an equivalent part number for £15, so that's currently on the way.

I'm running Bazzite rather than Windows, and it did detect the new resolution correctly, but when I try to force a custom resolution of 2560x1440@165hz it refuses to apply it.

I do actually have a dual boot of Windows on there, so I'll see if I get any better results with that

 

[Purgatory]

It's 40 pin on both end, so physically should fit, as you say, it's just if the motherboard isn't fully wired up, but since it came with a 240hz option, I would be surprised if that were the case, since I would have thought it would be easier to have a single motherboard for both options and just fit the appropriate screen

It will be fine then just get a 40 pin 4 lane cable and give it a go. Just make sure to grab a decent one not some random one and has some good reviews. Make sure the length is good too, to makes it easier to route back to the screen.