need help with AGP riser cable

[Ncc74656]

i have three riser cables from various companies, all hongkong so maybe same company. i swear i had it worked at one point but its been a while and now im not sure. Radeon 8500 and ti4600 on a G4 QS board. with the ribbon riser cable installed i will get a boot in os9 with out drivers. can use stuff just fine. however once i install drivers it seems to freeze durring boot.

in osx it will boot to just before the desktop refresh would occur and then ill get a mouse frozen in the upper left with a grey screen and my normal mouse currsor that i can move around. thats it.

i need to extend this agp port 7 inches.

thoughts?

 

[Byrd]

Are they Mac or flashed cards - you are dealing with the riser being compliant with AGP 1/2/3 standards and Apple ADC considerations too. You might need to tape some pins on the cards and/or check voltages

 

[Ncc74656]

Are they Mac or flashed cards - you are dealing with the riser being compliant with AGP 1/2/3 standards and Apple ADC considerations too. You might need to tape some pins on the cards and/or check voltag

the cards work direct in teh port. the riser is a 4X 8X type that sells a lot i guess. i have no other agp system to test with. the cards are both mac cards.

 

[Phipli]

the cards work direct in teh port. the riser is a 4X 8X type that sells a lot i guess. i have no other agp system to test with. the cards are both mac cards.

The 8x Mac cards are from G5s and tend to need modding to work in a G4?

Pins 3 And 11 - The Mac Elite

themacelite.wikidot.com

Plus a 7" extension will be... Not great for signal integrity.

 

[Byrd]

the cards work direct in teh port. the riser is a 4X 8X type that sells a lot i guess. i have no other agp system to test with. the cards are both mac cards.

The AGP slot in the riser is not electrically the same as the native onboard slot; you need to consider if the riser is compatible with 1.5V or 3.3V AGP cards, and potentially cover up pins, considering signaling is probably more sensitive on a Mac than a generic PC for which these risers are made for.

Mate can I recommend you put up one thread? I've enjoyed your posts here on your case mods, seen posts on Reddit, but nobody can track what your intentions across multiple threads and websites unless they've read what you've posted prior. Thank you!

 

[Phipli]

Now that it isn't 6am I see you said the riser is 8x, not the card.

But the slot is 4x, not sure what differences this makes. Also, Apple slots don't follow the standard pinout because they run power for ADC. If the extension makes these pins common, doesn't carry them, or tries to carry power through conductors only designed for data, you might have issues.

Plus potentially what Byrd was saying here.

The AGP slot in the riser is not electrically the same as the native onboard slot; you need to consider if the riser is compatible with 1.5V or 3.3V AGP cards, and potentially cover up pins, considering signaling is probably more sensitive on a Mac than a generic PC for which these risers are made for.

 

[Ncc74656]

yea the cards are mac and pc - they are all 4x cards. whats strange is that it boots with out a driver. so im thinking it must relate to opengl of some type - some kind of signaling issue perhaps. i know the agp ports are the same from pc to mac but the cable is not keyed as a universal. however im not sure how much that would matter? the port is a universal and the card is also so... those pins are missing anyway.

this is the cable i have 3 of im pretty sure. i think all the ones i ordered came from the same place. https://www.moddiy.com/products/AGP-16X-8X-Extension-Cable-Riser-15cm.html

 

[Ncc74656]

i did some further testing. my Geforce 2 MMX works to desktop. also runs cinebench on the riser card.
the riser only works with the key forward (3.3v) mode. the rear key is pinned on the riser but not on the cards so... i guess ill cut away those rear pins (1.5v) and see if that changes anything? i dont know if the MB is looking for a signal from the card or if its detecting those pins some how? the video cards are all universal so have both keys on them.

 

[Ncc74656]

i got the ti4600 to boot. im stress testing things now, x and 9.2.2 the 8500's will not boot off the riser for what ever reason... i have no idea.
i also dont know if this will be stable if its a signaling issue. but if its not stable... i cant think of what else it could be?

 

[Ncc74656]

well it seems to be mostly stable. occasional lockups but on the basic games it looks ok? its not in the final computer yet so... thats the next step, im still on my test bed.
once i get it in i need to work out cooling and then ill burn in a halo bench or something