HDD Major-Stuttering Solved (not micro-Stutt)

Technical Support
1 2 3 26 Next
Stuttering Problem Description:

The problem is that the game does not use "loading screens" to load all needed data from your hard disk drive (HDD) to your memory. Instead, the game is constantly reading from your HDD. Since other background running programs (including Windows) are also using your HDD while you are playing, it will cause your game to stutter. This happens because the game will have to wait for read/write access to your HDD.

Note: any stuttering caused by network lags (latency) is beyond our control. Huge number of enemies on one screen (+animations) will lower your FPS (this is common sense).

How I figured out this was the problem:

Basically, I noticed that my HDD had approximately 250ms (avg) - 1,500ms (max) read response time (RRT) for any read access to MPQ files located inside the folder:
"C:\Program Files (x86)\Diablo III\Data_D3\PC\MPQs"
I've tried defragmenting C: before and after installing Diablo3, but it didn't help with the slow HDD read response time. You can find your read response time in "Resource Monitor" in windows, or just type "res" in start menu. Just put the game in windowed mode and observe "Resource Monitor" > "Disk" > "Response Time" while you are moving your character around the screen and through different areas which normally stutters.

SOLUTION (Windows 7 or Vista):

1) You will need (minimum) 16GB USB flash drive (or 16GB SD card). An 8GB flash drive will not work because it will translate to 7.45GB under windows, which is smaller than needed (7.7GB).

2) Copy the entire "MPQs" folder (7.7GB) from:
"C:\Program Files (x86)\Diablo III\Data_D3\PC\MPQs"
to your USB/SD drive. For me, it was "D:\" drive, so the final result was "D:\MPQs". It might be a different drive name for you, so just use what you get.

3) Rename the original "MPQs" ( located on your HDD) to anything you want.

now the tricky part ...ready ?

4) Go to windows start > and type the following in the search box: cmd and hit (CTRL+SHIFT+ENTER), which will prompt you to run command line in administrator mode.

5) Once in command prompt, type the following (make sure you have the right letter drive):
cd "C:\Program Files (x86)\Diablo III\Data_D3\PC"
mklink /j "C:\Program Files (x86)\Diablo III\Data_D3\PC\MPQs" "D:\MPQs"

***Note: you cannot "CTRL+V" in command prompt, but you can right click "paste" instead.
***if you don't like this command-line stuff (step 4 and 5) you can jump to windows XP solution, but you have to install an extra program.

If you get a message that says something like: "a symbolic link has been created .." then you did it right. Your done!

SOLUTION (Windows XP) also works for windows 7/Vista (no command-line involved):

Follow steps 1 through 3 from windows 7 solution above
***Note: in windows XP, the "C:\Program Files\...." will not have the (x86) part.

4) Download a free program called "Link Shell Extension" from download.cnet website. This comes in two versions 32bit and 64bit. You have to install the right version depending on which windows XP you are using (most likely 32bit). After you install it, restart your computer.

5) Browse to the folder you created in step 3, for me it was "D:\MPQs", and righ-click on the "MPQs" folder, and select >"Pick Link Source".

6) Go to the original folder location on your hard drive:
"C:\Program Files\Diablo III\Data_D3\PC"
right-click anywhere inside the "PC" folder and select > Drop As ..> Symbolic Link ( or Junction).

Thats it! your done!

Basically, we faked the location of the MPQs directory and relocated it to a flash drive with faster read response than your HDD.

Now, you should have read response times (RRT) around 5ms !

ENJOY "stutter-free" Diablo 3 !!!!!!!!!!!!!!!!!!!
I am currently running it on a RAID 0 array of three WD 7200rpm drives which should be more than enough but I am getting the 1-2 second stuttering too often when a sound loads or when you go to the edge of the map.

I've now followed your instructions and put the MPQ folder on my SSD drive which I didn't really want to do since I only use this for caching and for my Operating System. I'll let you know if this fixes my issue once the servers come back up.

Even if it does fix it though, I still think this is something Blizzard needs to patch since there's hundreds of posts on this forum of people using a range of different mid-high end PC's getting the same problem. Some are even running the game off SSDs so I'm not too optimistic that this will work for me.
So you mean a flash drive?

I knew that soulstone USB had a purpose.
If this will not help, do i need to reverse the link somehow? Or it is enough to wipe it out of the flash/usb drive, rename the MPQ directory back to original, and forget about it?
Please blizzard we need a patch! I've been playing for 11 hours with consistent stuttering or lag what ever.. but Please Blizzard fix this graphic overload. I may get 20- 30 minutes of actual fun and 2 hours of crap and freezing up..
I have 1-3 second lock ups in animations before it "catches up", going to attempt this fix with a Sandisk Cruzer 16gb USB "thumb" drive. I will post results momentarily
i will try this now, hope it works...the game is barely playable for me with the slowdowns

if it works i will send you some beer :D
Okay did it on Vista, only difference is that you leave the 86 part out of the file path, if you want to know what your filepath is exactly, right click the path at the top of the window where the folder is and click "view as text" and just copy that.
When you create the link, on vista it says "Junction created for".... blah blah blah
Now, to see if it works....
Ok. I followed this instruction. I used simple USB flash drive.

What I got:
- notable reduction of "level-just-loaded-stutter" in the beginning
- reduced level-related stuttering (like in Oasis, Caldeum sewers). Actually, it is gone.
- game loading time reduced (screen with the flashing squares). Not if it was long, but now it's like... blink! - ready.

What I did not got:
- monster crowds fps impacts still presist. Basically, if there's A LOT of action (about 20+ monsters, skill using, corpses flying, meat, blood, violence) on the screen, fps still drops for me to around 25-28 from stable 60. My rig is not a top one, but this game technologically is fraggin prehistoric! I run BF3 on Ultra no problemo, but in D3 i got fps drops... Bravo, Blizz.
- micro-micro stutters still there. Almost unnoticable and quite rare. Compared to what I had before in Oasis, for example, it is a hell of a progress.

In general, yes, this solved "major stuttering" problem. Gamplay become smoother. Thanks a lot, Edstroyer.

P.S. My rig: AMD Athlon 620 x4 3,0Ghz (OC), MSI GeForce 260GTX 896 Mb, 4Gb RAM
Okay, it doesn't seem to be doing much. There may be a small difference in the 1-2 second delays. like half a second or so, but it's hard to say for sure. :*(
Maybe it is my use of the thumb drive, going to run out to the car and grab an sd card and try that....
Okay, sd card in el carro is only 4 gigs, running to Walmart/office max to pick up a bigger one. Might actually pick up a ssd if they have one just to see if it works.
Bubbles, did you try with a thumb drive as well or sd card? if you tried with an sd im not even going to waste the trip lol
Okay since I'm not getting a response from Bubbles, or even Conky for that matter :), I'm running out to pick up an sd card and/or ssd. I'll brb with more info. Stay tuned
i did it with my thumb drive 16gb
Okay cool beans, en route to pick up supplies for further testing. I guess Blizzards leaving this one to us. I'm totally sending them a scanned copy of my receipt and asking for reimbursement :p
there is a problem with this solution....somehow it just works for 1 gaming session, for the next login the game will download the MPQ files to the original directory....so it has to be redone every time you wanna play
Bubbles, are you sure you aren't just looking in the redirect folder and thinking its actually where it says it is?

BTW just got back with a PNY Professional 16 GB card with write speeds of up to 20 MB/s

Stay tuned for test results

As for spending money on it, meh. I have enough, and another SDHC card won't hurt to have around.

Join the Conversation

Return to Forum