PDF reader is realy slow on Mac M1 max

The scroll speed, loading speed and memory usage of the PDF reader are terrible on M1 max machines.
Since version 6 is released, when will it be natively built for mac silicon?
  • edited May 20, 2022
    That's not any sort of general issue — we're developing and running Zotero largely on Apple Silicon Macs, including M1 Max machines, and are not seeing those sorts of issues. If you're opening a particular PDF that's made up of large scanned images, performance may be a lot worse.

    (While it wouldn't be related to this, we expect to have an Apple Silicon version of Zotero ready this year.)
  • Can confirm similar issue since 6.0.8 at least. Zotero is currently the only app experiencing this sluggishness on my machine.
  • edited May 25, 2022
    You'd have to say more about what exactly you're doing when it's slow, what you have to do from a Zotero startup with no PDF tabs open to get it to occur, and what you're seeing in Activity Monitor.

    If you have any third-party plugins, you should test with those disabled.
  • edited May 25, 2022

    Test 1
    1. Add-ons enabled (Better BibTex, DOI Manager, Zotfile, Zutilo)
    2. Fresh restart, 1 tab open
    CPU spikes when highlighting (40-105%, vs. 2.5-4.5% when inactive)

    Test 2
    1. Add-ons disabled (all)
    2. Fresh restart, 1 tab open
    CPU spikes when highlighting (40-116%, vs. 2.5-4.5% when inactive)

    In both cases, scrolling caused smaller spikes, and just bringing up the highlighting dialog was enough to cause major lag spikes of up to 80% CPU usage.

    Spikes appear to be independent of the PDF being read. I tried a 320MB monster, a 1.3MB article, and a 445KB article. The differences were negligible.

    MacBook Pro (Apple M1, 8 cores, 16GB RAM)
    Zotero 6.0.8
  • Yes! Zotero is the laggiest pdf reader and almost the laggiest software on my 120Hz screen. When scrolling the article list and pdf, even pdf without any figure, it gets numerous frame drops. If pdf contains many figures, it loads every single page in almost a second when scrolling.
  • Just would like to add my 2 cents to this-- it's absolutely crazy how smooth the iOS app on a proMotion iPad.... but the proMotion M1 max just can't handle it.

    Test case: fresh machine, fresh Zotero install, 3 total files inputted in my library, no plugins.

    The closest I get to a smooth experience is forcing hardware acceleration on, but that's not a silver bullet.
  • edited June 8, 2022
    @paulmerritt: Not really sure what you mean here. What exactly are you saying the problem is? Again, we're running M1 machines ourselves, and we're not seeing any performance problems in normal usage.

    If you think something isn't right, can you take a screen recording that shows the problem, upload it somewhere, and provide a link here?

    (I also don't know what you mean by "forcing hardware acceleration on". Hardware acceleration is enabled in Zotero by default.)
  • @dstillman

    Basically, Zotero's pdf reader isn't hitting anywhere near the ProMotion cap of 120hz and it's most noticeable through stuttery scrolling. While I can't shoot in 120hz to show you with perfection, this 60hz, 59-second video should show you what I'm talking about and give you some comparison points. In this video, my Zotero has no addons and fully default settings.


    Also, I apologize. I misspoke-- I mean't forcing acceleration off, not on. I had this same problem on my PC, which was fixed through (https://forums.zotero.org/discussion/comment/369736/#Comment_369736) and it helps the Mac, but it's only a slight improvement.
  • @paulmerritt: Oh, so you're just talking about ProMotion scrolling? Zotero is currently based on an older version of Firefox, and it won't scroll above 60fps. We're working on a new version based on Firefox 102 (which will also be native on Apple Silicon), and that will go up to 120fps. It will also include a newer, faster version of pdf.js. Once we've rolled out that version, hopefully later this year, you should expect performance matching the online PDF.js demo. (It's unlikely that anything is going to be as smooth as Preview, though.)

    To be clear, this isn't about Zotero being "slow" in general, and doesn't have anything to do with Apple Silicon Macs in general — we just don't currently support high-frame-rate scrolling on ProMotion displays. And scrolling itself isn't actually slower — you can scroll as fast as you want. It's just the frame rate of the animation.
  • This is truly fantastic news!

    I’m glad I chose Zotero for my upcoming PhD adventure. Again, apologies for my unclear terminology but it seems like you worked around it.


  • Hi,

    Zooming with the trackpad is actually what's the most problematic, it takes at least half a second to register the zoom and it's very very sluggish.

    Other third-party apps which are not Preview manage to do it extremely well - just compare moving around a PDF in PDF Expert and in Zotero, it's day and night...
  • Greetings,

    "Zotero is currently based on an older version of Firefox, and it won't scroll above 60fps", which you mentioned above, i am still in trouble with the frame dropping of PDF reader within Zotero. Is there any possible to fix this problem before the release of native Apple Silicon version? sorry about my trouble with this problem~
  • I really hope to use the Apple Silicon version of Zotero soon. Hats off to all the developers!
  • Same here. I hope to use the native version before the first day of 2023. I've heard about it since probably May, 2022.
  • Same question still exist, it's now Apr 4 2023.
  • Experiencing the same issues on version 6.0.23. Everything else runs smoothly but Zotero, which has problems with scrolling, zooming, searching for papers, etc.
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