Performance Spikes and Drops Explaned

[Deleted4363562User]

Hey, guys, for those of you wondering about performance issues in Fallout 4, I got a really good reply from "goobers" over on the Nvidia Forums.

 

 

 

 

"Responding to high count draw calls isn't the issue... as the Titan X can supposedly handle up to a million in DX11, depending on the test (other tests are lower at 600k, which is still far more than 10k). But these draw call counts are worst case scenarios.

The issue is GENERATING those draw calls. That can suck up CPU cycles and who knows what else.

You assume all bottle necks are obvious. There can be a CPU bottle neck if it can't transfer data into and out of cache quickly enough... and you wouldn't see that as CPU usage, as that only indicates CPU doing calculations and managing the transfers, not the time it takes to actually transfer.

On the GPU side, it seems this game is designed around keeping the VRAM close to 4 GB no matter what card you use (750 or Titan X), it's quite likely that the draw call spike represents areas with more graphical data that requires more transfers into/out of the VRAM. If this is the case, then allowing the game to use more VRAM should alleviate the drop in performance for cards that have more physical VRAM.

Oh, in case you're thinking about the Fury X and it's HBM memory being faster, consider that the other end of the transfer (system RAM or SSD/HDD) is more likely to be the actual limiting factor in speed for non-HBM cards anyway."

 

 

So, this makes a lot of sense, because many users have reported minimal CPU and GPU usage in Afterburner.

[FishBiter]

How can I use this information to my benefit? o.o

[Deleted4363562User]

How can I use this information to my benefit? o.o

 

 

Honestly, I don't think there is anything we can do. Bethesda needs to patch the game to use more VRAM or we all need to buy CPUs that can transfer data for Draw Calls faster.

 

To be clear, I don't think overclocking really helps either. I overclocked to 4.5 Ghz to test, but it had no effect. I've heard of people with 4.8 Ghz having the same issues. Clock speeds won't change much in this case. It's the speed at which the data of these Draw Calls are transferred that is the problem. As far as I know, there isn't a CPU able to get past this. I'd be curious to hear more from people with newer high-end CPUs though. Maybe some of the ones with larger caches? I don't know.

[archtrtd1]

I'm glad to hear that it's not my computer build that's the problem. I'm very disappointed to find that there's nothing I can do about it until Bethesda/Nvidia chooses to fix these issues.

My specs are:

Asus X99 Deluxe (with latest bios)

i7 5930k (hexacore processor overclocked to 4.5 GHz with a 15MB cache) (watercooled with Corsair H110i gtx)

32gb DDR4 2666MHz Kingston HyperX Predator ram

2 Titan X Superclocked (SLI - with latest drivers)

480GB Sandisk Extreme Pro SSD

1200 watt Corsair AX1200i

Windows 7 Ultimate 64bit with SP1

2 Samsung 27" WQHD LED 1440p Monitors (I turn one off while gaming)

 

The size of the processor cache and the number of cores doesn't seem to help much in the performance of the game. Maybe it bought me a little more time before I started experiencing problems . . .

 

About twenty hours into my relatively problem-free gameplay I had two catastrophic crashes: one with an unresponsive black screen that made me briefly lose my main monitor (it took two reboots), and one blue screen that mentioned a video driver failure. I went back and CLEANLY reinstalled the new drivers AGAIN and I stopped having the catastrophic crashes. I managed to play for about 8 more hours with no problems (other than some occassional lag). Then the ctds, microstuttering, and lag began - most of which seem to occur in the downtown Boston area although I've had a few in other random locations and one in the crafting menu.

 

I have a few theories about the causes of our problems:

Quicksave/Autosave causing corrupt save files - don't use it because Bethesda clearly didn't fix these (my autosave files are about 1.2mb larger than my manual ones)

Nvidia needs to further tweak their BETA drivers (and provide a proper SLI profile for Fallout 4)

Possible memory leak - the longer your gaming session, the more likely you'll ctd

Glitched/conflicting questlines causing ctds in certain areas of the map

 

I would have thought the move to 64bit would've helped - but the persistent problems from Bethesda's previous games seem to have migrated along with the other assets they decided to reuse for this game. :sad:

 

Does anyone else have loading screens that go on forever? They are easly twice the length of time it takes my very HEAVILY modded Skyrim to load.