# The first generation is very slow (/docs/troubleshooting/first-run-slow)



A generation that takes twenty minutes on a card that should take three is usually not the card. Most of that time is spent reading the model off your disk before any generating starts, and a virus scanner sitting in front of that read can multiply it.

<Callout type="info" title="Who needs this">
  Anyone whose first local generation after opening SimpliGen is much slower than the ones that follow. It shows up most on video presets, because video models are the largest files.
</Callout>

## Is this your problem? [#is-this-your-problem]

It probably is if you recognise these:

* The **first** generation after opening SimpliGen is slow, and later ones are much faster.
* The progress bar sits still for a long time before any steps start counting.
* Your GPU sits near idle during that quiet stretch.
* Your models are on a hard drive, an external drive, or a network location rather than an internal SSD.

## The two-minute test [#the-two-minute-test]

Run the same generation twice, without closing SimpliGen in between.

* If the second run is much faster, nothing is wrong with your GPU. You were paying to load the model, and the fixes below apply.
* If both runs are equally slow, this is not your problem. See [Out of memory / stuck generations](/docs/troubleshooting/out-of-memory) instead.

## What is actually happening [#what-is-actually-happening]

Before a preset can generate, the engine reads its models into memory. A video preset can pull 10 to 30 GB from disk. Once loaded, the model stays in memory, so every later generation in that session skips the wait.

Two things commonly slow that read to a crawl:

* **The drive.** A mechanical hard drive or a USB or network drive is many times slower than an internal SSD. One user's log showed the model loading at 29 MB/s, which turned a 3.5 minute render into a 24 minute wait.
* **A virus scanner.** Windows Defender and third-party antivirus scan each file as it is read. On files this size that can cost more time than the read itself.

This is the difference people notice most when they come from a cloud tool. On a cloud service the model is already loaded on the server, so you never see this cost. Locally you pay it once per session.

## Fix it [#fix-it]

<Steps>
  <Step>
    ### Put your models on your fastest drive [#put-your-models-on-your-fastest-drive]

    Open **Settings -> Storage** and check where models are being stored. If that location is a hard drive, an external drive or a network share, move it to an internal SSD. Presets you have already installed can be re-downloaded to the new location.
  </Step>

  <Step>
    ### Exclude the models folder from your virus scanner [#exclude-the-models-folder-from-your-virus-scanner]

    In Windows Security, open **Virus & threat protection**, then **Manage settings** under Virus & threat protection settings, then **Add or remove exclusions**, and add your SimpliGen storage folder as a **Folder** exclusion. The path is the one shown in **Settings -> Storage**.

    If you use a third-party antivirus, add the same folder to its exclusion list instead. Model files come from the sources the preset declares and are verified on download, so excluding the folder does not leave you unprotected against anything the scanner would have caught.
  </Step>

  <Step>
    ### Run the test again [#run-the-test-again]

    Open SimpliGen fresh and run one generation. The first run should now start counting steps within a reasonable time rather than sitting still for many minutes.
  </Step>
</Steps>

## Still slow after the model has loaded? [#still-slow-after-the-model-has-loaded]

Then the generation itself is the slow part, which is a different question. Local video takes minutes, not seconds, and how many minutes depends on your card, the resolution and the duration. See [System requirements](/docs/getting-started/requirements) for what to expect, and [Out of memory / stuck generations](/docs/troubleshooting/out-of-memory) if it stalls near the end rather than running slowly throughout.

If long runs crash or freeze the whole machine instead of finishing slowly, that is the page file, not the disk. See [Increase your Windows page file](/docs/troubleshooting/page-file).