[riggs]

You should be able to power a 2.5″ drive using the Pi’s USB port. Depends one the drive’s power consumption though I guess.

Does your config.txt contain max_usb_current=1 ?

Could maybe be the PSU also. Any way of testing the output? It could be a cheap Chinese thing that doesn’t actually provide a good clean signal and/or the rated amperage. Have you got another PSU you could try?

[riggs]

Wing War..?

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Got some spare cash this month so I think I’m going to treat myself and replace all my HDMI cables with some nice QED ones. And yes, I know buying expensive HDMI cables is pointless (digital signal and all), but I’ve got other QED cables in the house and they’re great quality, so screw it…

;-)

If that doesn’t fix the lag I’ve spotted a cheap 21″ CRT on eBay. It’s just a case of seeing if the seller can test a 60Hz/NTSC signal on it.

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Right, I know I don’t HAVE to (4-pole 3.5mm jack and all)…I want to ;-)

The idea is to have a CRT with a built-in Pi, with the specific purpose of playing retro games. Depending on time/effort it’ll also have a custom SNES-themed paint job.

But like I said, that’s a project for later on.

[riggs]

Tried a couple of different men splits (256/768 & 512/512) but it didn’t make a difference. I’ve actually given up for the moment…I’m keeping my eye out for an old CRT TV that I can hack a Pi into. At least I know this will remove 2 frames of lag, then I can start messing around with the settings again and see if I can reduce the lag some more.

There was another member here who was also experimenting with different settings etc to try reduce the lag, but I think he gave up on it too. He was using a RealTime kernel version of Raspbian. I tried this and as far as I can remember, it shaved off one more frame. The downside is that at the moment, overclocking isn’t recommended on the RT kernel image; the SPI isn’t synced properly so overclocking the Pi also overclocks the SPI (which could be bad news if you’ve got anything (i.e., the ControlBlock) hooked up to the GPIO).

I think I’ve just become overly-sensitive to lag in my old age (!). The last time I messed around with emulation was maybe 7 or 8 years ago when I had an Xbox1 hooked up to a CRT. Played loads of NES/SNES games on that thing with my mates and never really noticed the lag. Since I started messing with all of this I’ve tried emulators on my Mac, a Windows machine, and even dug out my old PSP, and they all seem to have some sort of lag that, to me, is very noticeable.
I dunno…if I make any more progress I’ll post back here, but I’ve got more important things to sort out first (moving house, for a start).

[riggs]

Same as browner1980, I don’t have the solution, but have you tried editing your config file and changing the CONFIG_HDMI_BOOST setting? This increases the HDMI signal strength – default is 0, max is 7. The raspberrypi.org site recommends trying a value of 4 if you’re having signal issues.

There’s definitely something funny with the Pi’s HDMI. If I hook it up directly to my receiver (an Onkyo) it doesn’t work properly; I get signal drops every 30 seconds or so. However, routing it through a powered HDMI splitter first results in it working perfectly.

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retropie-v3.3-jessie-beta-rpi1
retropie-v3.3-jessie-beta-rpi2
retropie-v3.3.1-wheezy-rpi1
retropie-v3.3.1-wheezy-rpi2

[edit] They’re torrents btw…

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I also had problems with this; ended up being a combination of the CD image I was using and a dodgy syscard rom. Got it working in the end though.

I’m at work at the moment, but I’ll have a look when I get home and let you know what I did…

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And if you prefer torrents;

RetroPie v3.4 – Pi 1/Zero
RetroPie v3.4 – Pi 2

[riggs]

Hey dankcushions! Ok, cool. I’ll have another fiddle around with it at some point and see what happens.

Out of pure curiosity, I ended up downloading the RT kernel Raspbian that furntree mentioned, compiled RetroArch using his custom flags then proceeded to download/compile FCEUmm and see what happens. Performing the same SMB3 test I did in my other post I ended up shaving 1 or 2 frames off the input lag (mostly 2, sometimes 1, but this could’ve been a camera/TV refresh problem – my test isn’t exactly scientific!).

While that brings my lag down from 9 frames to 7 (or, 7 to 5 if you deduct the 2 frame lag my TV causes), it’s still a couple of frames off what furntree has accomplished. Granted, I’m testing a different core and I’m not exactly sure what his setup is. This is why I wanted an image of his SD. Firstly I’d want to run my own test using his setup. Secondly, it’d be interesting to use his setup as a starting point then, working backwards, start changing the settings to match my own and see which (if any) start causing lag.

btw, you’ll have to excuse my lack of knowledge on all of this. I’m still relatively new to the world of Linux. I’ve completed a few other Linux-based projects (NAS server, Hyperion box etc) but they were all mainly just a case of copying/pasting commands and hoping for the best!

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Hey furntree! Great job on fiddling with this. I’m in a similar position where input lag is killing the experience for me (getting a 7 frame lag on the NES/SNES cores (plus the 2 frames my TV adds!))

Any chance you could upload an image of what you’ve got working so far? I’m curious to know if the input lag can be reduced to a level that I would personally find acceptable. 9 frames just isn’t good enough for me. If I can get it down to 2 (plus the 2 from my TV) I’d be more willing to put more time into getting RetroPie up and running. As it stands, the stock image/script installer just don’t cut it imo.

Don’t get me wrong, I appreciate the effort that’s gone into this project and understand that the technical problems are actually related to Libretro/RetroArch, but I don’t really want to invest more time into this if it isn’t possible to reduce the input lag.

[riggs]

Disabling threaded video was one of the first things I tried, but it didn’t make a difference. AFAIk, GPU hard sync isn’t actually used on the Pi so I don’t think that setting actually does anything.

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[quote=113217]You sir, have conducted one of the best inout lag experiments I have ever seen, Why did I never think of hooking an led into the button circuit and then sit it in front of the tv and record.

Applause my good sir.

[/quote]

Thanks, although it wasn’t my idea; that magnificent bastard Ben Heck created an input monitor for an X360 pad (YouTube). I just hacked together an incredibly simplified version of this.

[Author]

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