IVe been wondering if allocating more RAM to a modpack makes it run better but when your in setting and going to allocate RAM it says that allocating too much RAM will cause performance issues and that I should only allocate more ram if its a heavy mod pack. Please someone help cause ive been lagging and most of the time im having lag spikes and my laptop has 8 GB of RAM the most FPS I ever got was 28.
Check mudpack sizes or specs and if the mods are big or it's a modpack you can make flexible to run then change the modpack up, look for a smaller modpack that adds the same or similar content but with different mods (or niche/small ones that do the same with) or make a custom one.
It depends, it can and mods do use up more, even Minecraft's current recommended specs are for 4GB of RAM. But I only allocate more if I want to get it running, in terms of better performance not really. If you want better performance change things like particles, render distance, smooth lighting, brightness, Vsync or with Optifine water, clouds and many other aspects, or use an FPS reducing/balancing mod.
RAM can help but tweaking other graphics settings can also help due to what needs to load and render. You could have it where the game doesn't run well with a high resolution resource pack or a large world save. Mods might be extra content but that's more the game has to load and render and consider alongside the Vanilla world gen, textures and other aspects.
Forge 1.13+ also got a reworking so it doesn't run as great as 1.12.2 and prior or 1.7.10. Fabric is a different story as it's more lightweight but even it if you have a lot of mods do have to consider how it runs with how many mods, how many assets/textures it's loading and so on I've said above. But with Fabric I can run more mods than I can with Forge in 1.14.4 before I have to be careful about the game and Windows even being able to keep up. Fabric I don't really have to worry but Forge I can put about maybe 20 mods (if many are big more so that's a thing to consider) and it just can't handle it.
I'm no expert with this stuff but I have used large and switched to more medium and smaller packs over time when considering how I used my 1GB of RAM PC (running up to 1.10.2 small custom packs I made alright but not well) compared to my now 8GB PC and later versions of the game.
I'd say if it doesn't change much with the Vanilla graphic settings or RAM allocation go with performance mods or lower the amount of mods you have. Obviously what has changed with modloaders (Forge or Fabric if counting 1.14+) and what Mojang has done between versions, and what's added in each is important to consider.
You can easily tell if the game needs more RAM - check what it says in F3, where the allocated memory should not reach the maximum (assuming that you do not set -Xms to -Xmx, which you shouldn't); for example (yes, even modded 1.6.4, albeit with my own highly optimized non-Forge mods, really only needs that much RAM; as you can see, I also get VERY good performance even at such a minimal allocation - memory only affects performance if there isn't enough of it, otherwise you are just taking away RAM from your system, as Java has to reserve the entire amount you give it, and possibly even reduce performance due to having to manage more memory, as well as possible disk swapping/decreased filesystem caching):
I use the following JVM arguments (based on older default launcher arguments, except that Xmx1G was lowered to Xmx512M and I added Xss1024K to increase the default 32 bit stack size to avoid MC-32168 (I've since patched this bug to prevent unlimited recursion). Ironically, I've gotten a "Minecraft has run out of memory" screen with 1 GB allocated, but not less, due to the Java process running out of process space - this is sometimes confused with an out of Java heap space issue but F3 shows plenty of free memory (I've seen people with 64 bit Java run into similar memory issues due to insufficient free system memory):
(I completely fail to see any reason why even the biggest modpacks, much less the latest vanilla update, would require more than 512 MB of RAM, perhaps 1 GB max allocated, with the exception of higher render distance/HD texture packs, as even e.g. 10,000 16x16 textures only requires 9.7 MB of RAM, and most blocks/items/entities are several KB each for their code (only instance variables/objects are allocated per entity, code and textures are only loaded one time. Of course, Mojang has made many poor design decisions since 1.8 in particular, like using an immutable object to store xyz coordinates, which need to be created millions of times per frame, but even then the memory requirements seem extreme (I've profiled the memory usage of 1.6.4 with VisualVM to see what uses the most and as expected the majority of memory is used by loaded chunks, in line with a calculated 10 KB per chunk section, plus a few more KB for heightmaps/biome/entity data (entities are actually fairly large but you usually don't have more than a few hundred loaded at once). Even a render distance of 32 (with Optifine) uses less than 1 GB (when this was added to vanilla in 1.8 it wouldn't let you go over 16 unless you allocated 2 GB)
I would really not say yes in the sametime I'll say yes.
I have an Low end computer (i5, 4gb, Intel HD graphics 2000) with optifine i can get alot of fps :120+. I can run 30 - 40+ mods with a bit lag then it goes to 120+ when i play long enough, without optifine I can get 60 - 50 fps. With shaders I get 60 - 70, with shaders + mods I can get the same fps when I play long enough
Depends mod to mod. I recall running it with J-map, JEI and Abyssalcraft. On 2GB, it would become a slideshow after a dimension switch (i.e. going to Nether). I upped it to 4GB and everything became peachy.
It depends on whether the game is running out of memory. Check the top right of the F3 menu, if the allocated memory is nearing the maximum, you might want to consider bumping it up, because if it is running out, it will struggle to read data quickly enough to maintain a good framerate, or outright crash.