Note: Delete the following 2 lines when you submit the issue. (Actually 4 lines. 2 sentences though)

Issue Description: Placing a Iron Backpack (Diamond backpack specifically, unsure if others were affected) into one of hotbar slots causes framerates to drop drastically.

What happens: Game lags.

What you expected to happen: Game not to lag.

Steps to reproduce (important):

1. Grab diamond backpack.
2. Place in hotbar.
3. Lag.
   ...

Affected Versions (Do not use "latest"):

• IronBackpacks: 3.0.5-6
• Minecraft: 1.12
• Forge: 2601
• Other Conflicting Mods (may be irrelevant to your issue):

Define "drastically". Does this happen with only Iron Backpacks installed?

Currently using FTB revelations, and just checked. It happens only when it specifically is selected.

You can see the ~10fps avg vs 140. My computer specs are there also, not playing on a potato.

Does this happen with only Iron Backpacks installed?

Yeah, isolating that issue is going to require that we confirm that iron backpacks (and nothing else) is causing it.

Nut: Somewhat related -> do you have a Nvidia GPU? I have AMD.

I have a GTX780. I have not noticed this issue. As for CPU, I have an i7-4790k.

Also try the default resource pack, I wonder if maybe that custom backpack geometry is accidentally super complex for example.

Ricket, you solved it. Selected the backpack and turned UI off, everything became normal. Contacting creator who patched Sphax for Iron Backpacks.

I would like to reopen this issue. I do not use a resource pack and am playing All the Mods 3 v. 5.8 that uses Iron Backpacks v. 3.0.5-6 and just having the diamond backpack on my hotbar drops 5-ish FPS and holding it drops 10-30 FPS. I had other players test this on the server and they had the same results.

Any resource packs? What upgrades are on the pack (does that influence it)? I'm afraid I'm going to need more details to have any hope of solving this.

P.S. Nice videos 👍

Thanks!
No resource packs. No upgrades but it is a storage focused backpack.

Can you duplicate the frame drop with just Iron Backpacks? I need to ensure it isn't a modpack issue.

I'll have to make an iron backpacks only pack tomorrow. I've shut things down for the night. I'll get back to you.

Can confirm only forge and iron backpacks install sees frame drops.

I've been seeing this also in the DW20 1.12 pack for a bit. When the diamond backpack is out, root.GameRenderer.level.hand goes from about 0.7% to 70% overall usage in the CPU graph.

Glad to hear that. Just wanted to elt you know that it only drops after opening, thought that might give a pointer. Thanks for all the hardwork - enjoyed the mod as part of sooo many modpacks.

I can report the same issue. Goes from 120 fps to 15 (!). Doesnt matter whats inside.

However holding it in your hand only causes the fps drop after the first time you open it.

(Tested this with a new game, SP, went Creative, gave me a diamond backpack.)

Thanks. This is high on my priority list of what to fix next.

Edit: It's the coloring code. Will try and get a fix out somewhat soon.

The new version is now live on CurseForge. I believe this issue should now be fixed, but let me know if it somehow isn't.