Let's provide some numbers ...
As Garyb explained, the rough calculation MHz need some caution.
On one side the core of the new DSP has been improved compared to the old one, so the performance of the new one should not only be seen from the MHz ratio. Checking Analog Devices figures in MFlops for example tend to show it.
The old ones (ADSP21065L) provide 198 MFlops for 60 MHz.
The new one (ADSP21369) provide 2 400 MFlops for 400 MHz (so 1 980 MFlops at 330 MHz).
The MHz ratio 330/60 = 5,5
The MFlops ratio (with same cMHz) 1 980/198 = 10 !!!
If you use this last figure, one Scope Pro with (14)/15 old DSP provide 15 x 198 = 2 970 MFlops
So your setup with 1 Scope Pro + 1 Pulsar II setup brings 4 158 MFlops
One Xite-1D then provides 6 x 198 + 4 x 1 980 = 9 108 MFlops
One Xite-1 provides 6 x 198 + 12 x 1 980 = 24 948 MFlops
With such figures 1 Xite-1D = 3 x Scope Pro = 2.2 x your setup
On the same level, 1 Xite-1 = 2.7 x Xite-1D = 8.3 x Scope Pro = 6 x your setup
Besides making calculation inside the same chip should be more efficient as it can spare on cycles needed to allow inter DSP chip data exchange on old cards. But as soon as you need to exchange data between DSP (to bring the data to the IO for example which muight sometimes be necessary, or to access to host RAM for delay and reverbs), then a bottleneck could also occure.
On the over side, some optimization might still be needed to achieve such result.
So maybe it would be reasonnable to lower the theorical ratio from 20% which brings think back to the 1 Xite-1D = 2.5 x 1 Scope Pro.
Then, 1 Xite-1D would be equivalent to 1.8 x your setup.
Then the I/O available should also be taken into account.
If your setup includes 1 SRB board (with no I/O), the Xite-1D can bring you what you had before with nearly twice the DSP power.
These figures are still theory as there is probably several parameter which could rise or lower the capabilities of the system depending on what you try to do, the plugs choosen, the way they are mapped to the DSP.
But to have a simple rough idea, 1 Xite-1D should provide the power of the most powerfull Scope PCI system.
And the Xite-1 should provide 2 to 3 times more power.
PS: that said, the Xite-1 still is the most economical solution in term of price per DSP power, as soon as you can afford it.
