No.
“Minimum KONA 3G System:
Power Mac G5 (dual) PCI-Express, 2GHz with 2GB RAM minimum for uncompressed SD or 4GB RAM for uncompressed HD. Ensure your Macintosh has a PCI-Express slot for compatibility. Use a Fibre Channel or SCSI external RAID for uncompressed SD/HD storage.” ( https://www.aja.com/support/konaNEW/kona-3g.php )
U see, that KONA 3G work on PPC G5 LATE)) I have this model with 4 PCI -EXPRESS(two 4x, one 8x, one 16x). On 16x stay graphic card, on 8x i put SCSI controller and in one of 4x PCIE KONA 3G. But I see on monitor from composite or HDMI only noise.
I don`t know how fight with this problem( I don`t wanna change KONA on Blackmagic because KONA 3G can play 4K. We shot movies on RED ONE and cut in APPLE PRORES 422 (HQ) not in RAW, but I know, that when we`ll do collorcorection sometime i`ll use RAW in 4K) Thank u)
Studio Bayrak. Ukraine.