Thanks for the feedback. I think I've narrowed down the problem to either HDD IO or perhaps CPU (idle/sleep). If I run top, before loading a couple of problems, I see the process being started stays in a sleep/idle state. Most of the CPUs stay idle as well. I don't know enough about SMP performance with OpenBSD to comment further. I just know, that the HDD IO compared to SSD on this system is considerably slower. I don't know if I have enough to file bug report other than speculation. I'm going to continue using Open on this system, and I'll see if these issues get ironed out. If it continues to annoy me, I suppose I could just use an SSD.
I have a spare SSD but its too small and old that I don't want to run an OS on. Let me just say, all the problems I had with load times, etc are gone with using the SSD.
The HDD I am using for Open has run IO intensive things quite well on another OS. The laptop I'm running Open on is also using an HDD with Gnome and it doen't have the same speed issues. It leaves me wondering if there isn't an IO problem with the chipset (edit: driver in OpenBSD). Another user on the mailing list recently trying to load Chromium with an AMD A8 w/ 8 GB complained of slow HDD IO and said it was also fixed using an SSD. The HDD IO, shouldn't be this bad.
Some in Open mailing list said amdgpu was slower on 7.x then 6.9. So after trying 7.1 and -Current (as of this weekend). Then I fresh installed 6.9. With 6.9, I removed gdm + gnome, disabled messagebus, gdm and used xdm + xfce. Somethings do load faster, but not as fast as would be expected on an HDD. The same setup on SSD gives the 'normal' expected HDD speed. My laptop with HDD is also running 7.x with Gnome on Intel graphics no speed issues there.
I've thought the blame was on amdgpu but I think it seems actually more with HDD IO (chipset? driver in OpenBSD* ) or maybe CPU state (idle/sleep) . I've tried tweaking londer.conf, sysctl.conf and such to no avail.
*edit: I write this because I dual-boot this system, and the other OS uses an HDD and SDD and no disk IO problems. In fact, I've also tried FreeBSD and some Linux distros, also no problems even with the same HDD.