How fast is the HP Prime?
03-10-2014, 07:34 PM (This post was last modified: 03-10-2014 07:44 PM by jebem.)
Post: #8
 jebem Senior Member Posts: 1,355 Joined: Feb 2014
RE: How fast is the HP Prime?
(03-10-2014 03:07 PM)HP67 Wrote:
(03-09-2014 07:17 PM)jebem Wrote:  When we look to the venerable and powerful HP-50G, we understand the costs of Saturn emulation... more than 60 seconds to compute the same integral!

I didn't bother looking at the video but from your description this is not an apples-and-apples comparison. There is nothing to conclude from it except relative device speeds, all things being unequal.

The 50g is Saturn emulated on 75 MHz ARM. The only way to truly understand the cost of emulation in the 50g is to fab a 75 MHz Saturn processor and run them side by side. Otherwise, you're comparing a 400 MHz ARM device running native code against who knows what. Did you not expect it would be faster even against a 75 MHz device running native code?

Did I miss something here?

1) Hi, HP67! I understand your point.
Of course HP Prime is faster! That is exactly my point: HP has done an excellent choice of hardware and software components for the Prime, and the benchmark just prove it!
Otherwise, the benchmark results would be poorer for the HP-Prime, even running at 400MHz.

And please let's not generalize and jump to conclusions: this benchmark is only valid for the above equation, nothing else.

2) Concerning your observation on the costs of emulation: I agree with you, of course. We cannot compare apples to apples here, as we do not have a native 75MHz Saturn processor.

However, let me do some basic analysis here:
I have run the benchmarks myself on my HP-50G and HP-Prime, after seeing the video:

- Let us say the HP Prime takes 0.1 Sec to come out with the result (and I can guarantee it is taking less than that: the answer is instantaneous. Try it yourself to check it).
- The HP-50G takes about 65 sec.

- Calculation speed ratio of: 65/0.1 = 650 times faster for the Prime.
- Raw clock speed ratio: 400 MHz / 75 MHz = 5.3 faster clock in the Prime.
So, for a 5 times faster clock, the Prime is 650 times faster.

Analysis:
The poor HP-50G performance root cause is not the lower clock speed.
Make your choice(s) for the root causes:
- Saturn emulation.
- Inefficient Saturn cpu architecture;
- Poor choice the host ARM processor for the job;
- Inefficient HP-49 series algorithms when compared with the ones implemented in the Prime.

Jose Mesquita