New PixInsight 1.9.4: overall ~30% faster on Apple Silicon

Equipment Processing Astronomy tools News Review
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Willem Jan Drijfhout avatar
Willem Jan Drijfhout avatar

As many will probably know by now, PixInsight released a new version (1.9.4) this week. The main change is a new and modern underlying javascript engine. This change offers performance gains across operating systems. But for Macs with Apple Silicon in particular this upgrade was crucial, as it was a necessary step for a native Apple silicon version of PixInsight. And that is crucial because the next MacOS will not support non-native applications anymore.

After upgrading my Intel-based Mac yesterday, today I took the plunge and updated my Apple Silicon Mac (MacBook Pro M2 Max with 64GB RAM). The results are absolutely fantastic. A complete WBPP run with 160 full frame (60MP) images was finished in 2/3rd of the time it did under the previous version. Just some numbers to compare:

WBPP overall - 1:27:50 > 59:48 - 32% faster
Calibration 100 lights - 7:55 > 5:55 - 25% faster
SubframeSelector - 6:06 > 3.52 - 37% faster
Registration 72 frames - 4:44 > 2:45 - 42% faster
Local Normalisation 72 frames - 12:44 > 8:16 - 35% faster
Integration 72 frames - 7:03 > 5:01 - 29% faster
BlurXTerminator - 24s > 23s - 4% faster
StarXTerminator - 40s > 38s - 5% faster
NoiseXTerminator - 22s > 21s - 4% faster
SPCC - 22s > 14s - 36% faster

The XTerminators don’t seem to benefit too much from this upgrade, but all the other steps are about a third faster than before. And the application definitely feels snappier than before.

A big thank you to the PixInsight team for a big leap forward in performance and for a native ARM-version. And this upgrade is free for all PixInsight users, very nice.

There has been a lot of commotion on the internet around this upgrade. Third party scripts also have to be updated to work with this updated version on Apple Silicon (other operating systems and Intel-based Macs work fine with the old scripts). The two main 3rd party script sources for my workflow are Cosmic Photons and Seti Astro and both had their scripts already updated at time of release or at least within 24h thereafter. So thank you Mike and Frank! As far as I could tell they all worked fine. Still having an issue with GraXpert, but looking at the Github site that issue is being ironed out as well. So based on my first experiences, all this commotion is unnecessary. There will always be teething issues with every big release of every new software. But so far for me the transition has been very smooth.

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Eric Gagné avatar
Eric Gagné avatar

I think you are not seeing much improvement in RC-Astro’s tools because they are processes, not script so they don’t benefit from the new V8 JS Engine.

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Michael avatar
Michael avatar

Eric Gagné · May 15, 2026 at 05:23 PM

I think you are not seeing much improvement in RC-Astro’s tools because they are processes, not script so they don’t benefit from the new V8 JS Engine.

And all 3 (BXT, NXT, SXT) are since years running natively on Apple silicon. So the performance improvement is already done.

Marcelof avatar
Marcelof avatar

Michael · May 15, 2026 at 05:55 PM

And all 3 (BXT, NXT, SXT) are since years running natively on Apple silicon. So the performance improvement is already done.

Exactly. Russ had already been running his XTs natively for a couple of years.

John Hayes avatar
John Hayes avatar

Thanks for the report! The internet at my house went flaky this week so I put off doing the upgrade until I could get it fixed. Turns out that the co-ax’ cable to my house had become sun-rotted and moisture got in through the cracked rubber, which caused massive havoc with signal stability. I’m eager to try out this new upgrade but now I’ve got to head out of town for a couple of days so I have to put it off one more time until I get back.

I’m looking forward to the speed increase on my Mac but I’m also hoping that they have fixed some of the stability issues. PI does not appear to be very well behaved when the memory limits get stressed and I experience crashes all the time. I’ve seen this both on my Mac machines AND once on my Windows machine. I’ve gotten the brush off when I mentioned this on the PI support forum pages but I’m not convinced that it’s a problem confined to me only. I’m about to upgrade to a new M5 Max machine with as much memory as I can stuff into it. Hopefully that will help as well…at least up until I upgrade my camera to an IMX461 based sensor! :)))

John

Willem Jan Drijfhout avatar
Willem Jan Drijfhout avatar

Haven’t done nearly enough testing to say something about stability. I have the Qt-issues from time to time, so hope those will be over. I remember crashing in the past but that was when I was playing with RAM disks as extra swap drives. Gone back to standard settings for swap drives and not had much issues since.

Are you going for the M5 Max? Not rather wait a few months and get the M5 Ultra?

WJ

Willem Jan Drijfhout avatar
Willem Jan Drijfhout avatar

Michael · May 15, 2026 at 05:55 PM

Eric Gagné · May 15, 2026 at 05:23 PM

I think you are not seeing much improvement in RC-Astro’s tools because they are processes, not script so they don’t benefit from the new V8 JS Engine.

And all 3 (BXT, NXT, SXT) are since years running natively on Apple silicon. So the performance improvement is already done.

Yes you are right. They are so much faster on my M2 Max than on my Intel-based MacPro.

Richard avatar
Richard avatar

Thanks for reporting these results, always nice to see improvements across other platforms!

With my Windows laptop I can utilise my graphics card via CUDA acceleration to speed up the RC tools. Is there an equivalent acceleration option with Mac or does it work well right out of the box (the times you listed are on par/similar to my Windows laptop).

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Willem Jan Drijfhout avatar
Willem Jan Drijfhout avatar

Richard · May 15, 2026 at 07:25 PM

Thanks for reporting these results, always nice to see improvements across other platforms!

With my Windows laptop I can utilise my graphics card via CUDA acceleration to speed up the RC tools. Is there an equivalent acceleration option with Mac or does it work well right out of the box (the times you listed are on par/similar to my Windows laptop).

Like others also mentioned, the RC tools are native Apple Silicon applications. I believe that means they make use of the standard graphics acceleration that is baked into these combined CPU/GPU chips. The Apple Silicon chips handle AI and Machine Learning algorithms exceptionally well.

Nothing special on my machine. It is a MacBook Pro with M2 Max, that is a three generations old chip.

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Marcelof avatar
Marcelof avatar

John Hayes · May 15, 2026 at 06:14 PM

Thanks for the report! The internet at my house went flaky this week so I put off doing the upgrade until I could get it fixed. Turns out that the co-ax’ cable to my house had become sun-rotted and moisture got in through the cracked rubber, which caused massive havoc with signal stability. I’m eager to try out this new upgrade but now I’ve got to head out of town for a couple of days so I have to put it off one more time until I get back.

Keep in mind that some scripts haven't been ported yet, especially those that have been abandoned by their developers—such as the popular GAME script, which is very unlikely to be ported. Other active developers have decided, for various reasons, not to update their scripts, as is the case with DBXtract.

On CN (yes, I know) there’s a thread about which scripts have been ported:

https://www.cloudynights.com/forums/topic/1000368-pixinsight-194-scripts-status-tracking-thread/

(Copied from the semi-official post on Facebook, but I don’t have an account there)

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Paul Sanfilippo avatar
Paul Sanfilippo avatar

I would be keen to update for the potential processing speed improvements, but I do use DBXtract a bit. This no longer works in 1.9.4? Are there any other scripts that we know don’t work?

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Tom Boyd avatar
Tom Boyd avatar

Paul Sanfilippo · May 16, 2026 at 02:01 AM

I would be keen to update for the potential processing speed improvements, but I do use DBXtract a bit. This no longer works in 1.9.4? Are there any other scripts that we know don’t work?

I updated on my M1 Mac Mini, and DBXtract still works. I guess because I still have Rosetta installed and it’s still supported on the current Mac OS.

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Eric Gagné avatar
Eric Gagné avatar

The scripts don’t have to be ported to run in 1.9.4 for the moment, the old JavaScript engine is still in it. It’s only in the MacOS ARM64 that it won’t work. With the Linux , Windows and MacOS x64 versions the scripts can work. The developers only need to add a directive at the top of their script to explicitely tell PI which engine to use.

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Paul Sanfilippo avatar
Paul Sanfilippo avatar

Eric Gagné · May 16, 2026 at 02:49 AM

The scripts don’t have to be ported to run in 1.9.4 for the moment, the old JavaScript engine is still in it. It’s only in the MacOS ARM64 that it won’t work. With the Linux , Windows and MacOS x64 versions the scripts can work. The developers only need to add a directive at the top of their script to explicitely tell PI which engine to use.

Thank you, but I’m getting a bit lost. I have a M2 Mac Studio. When I start PI, I get:

PixInsight Core 1.9.3 Lockhart (x64) (build 1646 | 2025-04-02)

that’s not the ARM64 version right? So I should be ok to update and not have issues?

edit: Ok I think I understand. So if I stick with the x64 version I can update, not have any script compatibility issues, but not get the speed benefit of native silicone which is the ARM64 version, right?

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Eric Gagné avatar
Eric Gagné avatar

Paul Sanfilippo · May 16, 2026 at 02:56 AM

edit: Ok I think I understand. So if I stick with the x64 version I can update, not have any script compatibility issues, but not get the speed benefit of native silicone which is the ARM64 version, right?

Not exactly. The x64 version can run the current scripts because it still has the old sm engine but by default it uses the new V8. For scripts to work without being ported, their developers need to add 1 line of code at the top to tell PI which engine to use.

In a nutshell the script needs to begin with
#engine sm

If it does not have that then PI will us the new V8 engine which the “old” scripts won’t work with.

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GalacticRAVE avatar
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Eric Gagné · May 16, 2026 at 03:12 AM

In a nutshell the script needs to begin with
#engine sm

If it does not have that then PI will us the new V8 engine which the “old” scripts won’t work with.

Eric: actually no, the ARM PI1.9.4 simply has no javascript sm engine

GalacticRAVE avatar
GalacticRAVE avatar

besides the speed gains already being mentioned:

look and feel is much better - windows even of large files pop up immediately. QT errors appear to be an issue of the past. So far haven’t seen a crash yet even in extended sessions (to be observed …)

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Mike Cranfield avatar
Mike Cranfield avatar

Paul Sanfilippo · May 16, 2026 at 02:56 AM

Eric Gagné · May 16, 2026 at 02:49 AM

The scripts don’t have to be ported to run in 1.9.4 for the moment, the old JavaScript engine is still in it. It’s only in the MacOS ARM64 that it won’t work. With the Linux , Windows and MacOS x64 versions the scripts can work. The developers only need to add a directive at the top of their script to explicitely tell PI which engine to use.

Thank you, but I’m getting a bit lost. I have a M2 Mac Studio. When I start PI, I get:

PixInsight Core 1.9.3 Lockhart (x64) (build 1646 | 2025-04-02)

that’s not the ARM64 version right? So I should be ok to update and not have issues?

edit: Ok I think I understand. So if I stick with the x64 version I can update, not have any script compatibility issues, but not get the speed benefit of native silicone which is the ARM64 version, right?

Paul

You can safely use the x64 versions of PixInsight 1.9.4 - all current scripts and processes should work fine. They need no modification to do so.

To get a bit more geeky … there is no need for existing scripts to add the “#engine sm” directive to run under x64 versions of 1.9.4. Here is an extract from the official PixInsight script porting guide:

“The script will be executed on the legacy SpiderMonkey JavaScript runtime. This is the default execution mode when no #engine directive is specified, so using this selector is not necessary. The sm engine selector exists for completeness.”

The arm64 version for Mac is different. That version does not, in fact cannot, include the legacy SpiderMonkey engine. So only use that version if all the third-party scripts and processes you find essential for your workflow have been updated. Note here, not just scripts but all third party processes also need to be updated for the arm64 version.

I do know all my cosmicphotons processes and scripts have been updated and so have all the RCAstro tools. Furthermore you do not need to change your repository addresses to pick up the new versions.

I hope this helps

Mike

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Rob Pettengill avatar
Rob Pettengill avatar

My M1 MacBook runs the PI benchmark 27% faster. Startup is dramatically faster. The big improvement is over 2X in a long WBPP run! This is on an M1 MacBook Pro Max with 64GB of RAM.

I just reran a WBPP pre processing run, 155 25MP OSC dithered images BB and dual NB with 2X drizzle stacking and the best quality options in WBPP. It took 3.08 hours with the Intel code and Rosetta. The Apple Silicon native version took 1.35 hours, 2.28x faster for this Weighted Batch PreProcessing run!

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Eric Gagné avatar
Eric Gagné avatar

Mike Cranfield · May 16, 2026 at 09:43 AM

The script will be executed on the legacy SpiderMonkey JavaScript runtime. This is the default execution mode when no #engine directive is specified, so using this selector is not necessary. The sm engine selector exists for completeness.”

Mike

I guess I misunderstood what I read then. Thank you for correcting me on this Mike.

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Paul Sanfilippo avatar
Paul Sanfilippo avatar

Thank you Mike and all,

Just to be clear (unless I have missed this), speed gains will only be realised with the ARM64 version?

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Mike Cranfield avatar
Mike Cranfield avatar

Paul Sanfilippo · May 16, 2026 at 10:51 AM

Thank you Mike and all,

Just to be clear (unless I have missed this), speed gains will only be realised with the ARM64 version?

It is broadly true that the big speed improvements for Mac will be in using the arm64 version. However, as developers start using the new V8 engine for scripts there is the possibility of significant performance improvements in some cases on x64 versions.

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