Powerbasic Museum 2020-B

General Category => General Discussion => Topic started by: Theo Gottwald on July 14, 2013, 06:35:37 AM

Title: PB Compiler Speed considerations
Post by: Theo Gottwald on July 14, 2013, 06:35:37 AM
Bob used a lot of time to speed up the compiler.
As I see it, that was one of his major goals to have the fastest compiler far and wide.

I have had some trouble with older hard-drives so i had to do some changes here.
After these changes i can tell you what REALLY makes PB faster, and what doesn't.

First thing i tried, was to move a large PB Project from a
Intel Core2 Quad Q9650 @ 3.00GHz with a Speed-Rating of 4248  (http://www.cpubenchmark.net/cpu_lookup.php?cpu=Intel+Core2+Quad+Q9650+%40+3.00GHz&id=1050)
to a
Intel Core i7 975 @ 3.33GHz with a Speed Rating of 6267.
in fact a much faster CPU with a larger Cache.

The point about this was that the hard disk of this later system was slower.

The Result was poor. This proofed me, that the compile-times of Power-Basic are not that much CPU dependend, but much more dependend of the speed of the hard drive.

I have then added a SSD to the system and placed the PB Folder and the Includes (Jose's includes) on this SSD.
Not the fastest available SSD, but with an access time of 0.1 ms / 450 MB/s Max. Speed.
Result was that Compile time broke down from 5 seconds to 3.5 seconds.

This shows that the actual PB compile times are to a large degree just the loading times of those many include files.
Buying for example "just a faster" even twice as fast CPU may not lead to a much faster compilation.

It looks to me that the assembler core of the compiler is that fast that it does not play a significant role in compile time - even in large projects. It seems that the hard drive plays the largest role.

My impression is, that a system with a low Access time (SSD) leads to a higher speed up, then a system with a higher maximum Data transfer rate. To get the most speed out of your PB Compiler, what you need is a SSD.

While this here is from my new my Reserve PC, that i may test later.
(https://fbcdn-sphotos-g-a.akamaihd.net/hphotos-ak-ash4/998813_442983742466916_2033815936_n.jpg)

This looks like the perfect choice. :-)

(https://fbcdn-sphotos-g-a.akamaihd.net/hphotos-ak-prn1/1017608_134727470065589_1427350365_n.jpg)
(Write Back Cache enabled Intel Raid)

These two diagrams show the speed difference between Cached Data and Data from Hard drive.
If you take a look on the numbers, its easy to understand why the hard disk subsystem plays a heavy role.