Quicksilver is a performance modpack that attempts to be a stable base for most mods. This speeds up vanilla significantly, and will run on as low as 512mb of memory, and on lower end systems.

(the name is a riff on the periodic table mods if you were curious :P)

How does this compare to Simply Optimized? Why Forge not Fabric?

Simply Optimized runs on Fabric instead of Forge, so they have access to a few mods that are unavailable for Forge and most likely will improve your performance compared to this pack. The caveat here is that while Fabric and Forge are catching up in terms of compatability, many mods are still Forge only, and as this modpack is supposed to be a base modpack with other mods added on top of it, Forge is a better option for this particular use case.

Why 1.19.2 and not 1.19.4?

This is for much the same reason that this modpack is on Forge not Fabric, most mods have chosen 1.19.2 as their version of choice, so this modpack is stuck on 1.19.2 for the time being. This is not only true for mods external to the pack though, many of the performance mods included are only for 1.19.2 as well.

Why not [Mod]?

Smooth Boot? while on other systems it may significantly improve load times with my personal testing it only decreased them
Phosphor (Radon)? Starlight is a better alternative and is generally faster.
FixMySpawnR / Let Me Despawn? These mods change vanilla behavior quite a bit, and while they do increase performance, doing that at the cost of vanilla features is not a goal of this pack.
- But Alternate Current? Alternate Current is a mod that changes the redstone engine of minecraft, and unfortunately that can break some very rare redstone. It mainly will break location specific redstone, some 0-tick designs, and some tnt-dupers. I feel the trade off is worth it in this case, as it doesn't break features that are used commonly in vanilla, only by high level redstoners like those on SciCraft or similar servers, who are unlikely to use this pack regardless.
Distant Horizons? While the idea behind this mod is very interesting, and I've had some success with the mod, it nearly nullifies the effects of Enhanced Block Entities and for me that is quite the deal breaker as modded minecraft is full of block entities, and therefore are really important to be optimized. I've left the mod's config in the pack if you would like to add it yourself, but know that it will not be supported.

Okay, that's cool and all but where are the numbers?

For me (see specs below), I get the following load times (after the first load):
On 512mb: 2.67 to main menu, and 15.79 to world load
On 1gb: 2.50s to main menu, and 15.46 to world load

But that's just the pack by itself, what about with other mods?
I added this modpack to ATM 8 and here are the results:
Default (without the pack): 2m 30s to get into the menu, and an out of memory crash when trying to generate a world
On the first load (with the pack): 2m15s to get into the menu, and 3m31s to world
On the second load (with the pack): 54s for menu, and 2m12s to world

Specs (as given by F3):
- 11th Gen Intel(R) Core(TM) i5-1135G7 @ 2.40GHz
- Mesa Intel(R) Xe Graphics (TGL GT2)

The modpack isn't performing well for me, why? Well are you:

Using the "Fast" quality setting in video settings? I'm not quite sure why but this will cause significantly choppier framerates (especially under low memory conditions). Use "Fancy" instead it preforms much better in most circumstances.
Using less than 1gb of ram? While yes, the modpack will perform quite well under 512mb, if you can spare it, one gigabyte of ram will make the modpack run incredibly smoothly.
On your first load? Lightspeed seemingly decreases performance on your first load, but if on successive loads it will get much much faster.

Full Modlist

Library Mods:
- Placebo : Needed for toast Control, FastWorkbench, FastFurnace, and FastSuite.
- Cloth Config API : Required by REI.
- Architectury API : Required by REI.
- Reforgium : A port of the fabric rendering api, used for Enhanced Block Entities Reforged
- Searchables : Used for Controlling.
General Quality of Life Mods:
- Controlling : The mod that lets you search through your keys.
- Bad Wither No Cookie - Reloaded : Sliences global sounds.
- Toast Control : Supresses those annoying tutorial hints, and recipe unlock notifications.
- Roughly Enough Items (REI) : I'm sure you're famillar with this one by now :P
- Shutup Experimental Settings : Disables the “Here be dragons!” dialogue when opening a world.
- Game Meny Remove GFARB : Removes the “Give Feedback and Report Bugs” button as, well, nobody uses this and should not be used in modded enviroments.
- Catalogue : A fancy modlist mod.
- Configured : A fancy mod config mod.
- Lucent : A dynamic lighting mod, while this is divisive if this could be considered QoL or a feature Lucent is by far one of the best (and fastest) dynamic lighting mods, so I found it fit to include here- disable it if you wish.
- Exit Confirmation : For butterfingers such as myself, who did not mean to close minecraft, and accidentally lost hours of work.
- No Chat Reports : Removes chat reports.
- Accurate Block Placement Reforged : Changes block placement to be more similar to bedrock allowing for faster block placement.
Optimization Mods:
- AI Improvements : While not nearly having the same effects as it does today, this mod is still somewhat helpful.
- Clumps : Groups xp orbs into one, reduces lag from xp orbs.
- FastWorkbench : Speeds up crafting recipes.
- FastFurnace : Speeds up furnace recipes.
- FastSuite : Speeds up recipes in general.
- Get It Together, Drops! : It's like clumps, but for items instead of xp.
- FerriteCore : Memory usage optimization mod.
- LazyDataFixerUpper (LazyDFU) : Reduces loadtimes by making the DFU- the system to convert old worlds into modern ones- lazy.
- Starlight : A rewrite of the minecraft lighing engine.
- Ksyxis : Makes worlds load faster by not waiting to load the chunks around you.
- Alternate Current : A rewrite of the minecraft redstone engine.
- Better Fps - Render Distance : Changes render distance to be a circular radius and not a square one, resulting in an fps boost with almost no visable impact.
- Entity Collision FPS Fix : Skips some unnecessary checks on the client that the server already does.
- No See, No Tick : No see, No tick. A mod extreme version of simulation distance in vanilla :P
- ImmediatelyFast Reforged : A mod improving the immediate mode rendering performance, this should improve performance with mods such as Immersive Portals or other similar mods.
- CullLessLeaves Reforged : Cull leaves but prettier and faster.
- Enhanced Block Entities Reforged : A mod that improves performance around large quanities of block entities.
- Lightspeed - Launch optimizations : Makes loadtimes after the first much faster.
- ModernFix : A boot time and memory reducing mod.
- Periodic Table Mods :
  - Rubidium : A port of Sodium, a client rendering optimization mod.
  - Canary : A port of Lithium, a server optimization mod.
  - Pluto : A port of Krypton, a networking optimization mod.
  - Saturn : A port of Hydrogen, a memory optimization mod.
Bugfix Mods :
- Memory Leak Fix : Fixes some memory leaks, could be considered an optimization mod.
- AttributeFix : Allows attributes to go over their vanilla limits, essential for some mods to work

~~wow optimization doesn't sound like a word anymore~~

Mercury - Quicksilver