• Software
  • The Case of the Mysterious Presentation Font Cache CPU Hog
2012/08/05 02:01:46
Kreative
My computer was starting to fry up and actually shut down a few times due to a Microsoft NET Framework service that had somehow become corrupted and was-unknown to me at first- running in an infinite loop. Yes. And it was very troubling at first because I had no idea what was going on: the fan going out, dust build up in the fan or heat sync, or any number of other things.

Anyway this has happened to a lot of people and I just wanted to post this in case it may happen to you. http://blog.tune-up.com/myth-buster/the-case-of-the-mysterious-presentation-font-cache-cpu-hog/

"Your PC worked perfectly fine the other day, but suddenly, it’s acting up. Performance went down, CPU activity increased, and your laptop’s or desktop’s fan is going wild—there’s clearly some resource hog affecting your system.


The Presentation Font Cache is part of the Windows Presentation Foundation (WPF) feature, which allows programmers to develop graphically richer applications. It’s part of the .NET Framework (3.0, 3.5, 3.5 SP1 and 4.0), which, in turn, is part of Windows Vista (3.0) and Windows 7 (3.5).


Some of your installed applications may require WPF and make use of the Presentation Font Cache. This service loads font glyph information into memory and helps share these fonts with all of the installed WPF applications. As such, applications that use the WPF framework start a bit quicker, and font pickers (such as this one) might see a slight performance increase.


Why is it burning my CPU? The Presentation Font Cache loads all fonts into its font cache (which is stored on your hard disk, but more on that later). However, at some point, this cache may become corrupted and unreadable due to a specific font. Then, the Presentation Font Cache will start to become unresponsive and get caught in a “I try to launch, but I’m stuck, so I will try it again” loop. That’s what causes the incredibly high CPU usage, and what may even result in a sudden shutdown due to overheating. Luckily, there are a few solutions to this problem!" http://blog.tune-up.com/myth-buster/the-case-of-the-mysterious-presentation-font-cache-cpu-hog/


Today my core temperatures are running from 58 to 65 C compared to days ago when-I was only using the Internet- they got up to the 80's and higher at one other time, finally shutting down at around 100C, the TJ max.

2012/08/05 08:55:04
Danny Danzi
Thanks for posting this, it's good to know. I'm no computer expert but I would think you still have some sort of cooling issue with the temps you've mentioned. I know some processors run a little hot anyway, but man....58-60 C just surfing the net? That has to be considered pretty high.  At least it is for me.
I have 6 pc's and a laptop that are always on in my studio. We have "stations" where we can send stuff too when other pc's are rendering. My main 4 work-horses look like this:

Dell Inspiron, 4 gig RAM, i3: (I'm on this now) 29 C while typing this. With a decent audio project going, and IE open, 34-36 C. Video render, 58-65 C. I keep my room between 70 and 72 F

Jim Roseberry recording pc, 12 gig RAM i7 Win7 x64: 41-43 C at idle, 45-49 C with a large Sonar project. 60-65 C with a video render.

Danny D custom box, 16 gig RAM, i7 Win7 x64: 43-45 C at idle, 47-49 C with a large Sonar project, 60-65 C with a video render.

Dell quad core laptop, 4 gig RAM Vista x32: 41 C idle, 42-47 surfing the net, 44-48 with a large Sonar project.

As you can see, I can't even get close to those temps you've listed unless I'm doing a video render. I've not messed with turning off any font cache. Though I see cpu spikes once in a while and hear my fans kick up a little, at idle my cpu is always at 0% when I'm not doing anything.

I'd definitely consider a different cooling solution or open up your system and check for dust or clogged heat sinks/fans or blocked vents. As I said, I'm no expert but I know a little something about these things. If I were you, I'd definitely be concerned with numbers like that from just surfing the net. I'm not even remotely close to the temps you are seeing other than video rendering. What would happen if YOU did a video render using Windows movie maker, Vegas, Camtasia or something to that effect? You'd probably over-heat or come darned close. Definitely look into this a bit further, Kreative. I may be over-reacting here, but I would look into some better cooling options because those numbers you listed are what I'm getting with my pc's all pushing super hard. I'd not want to see those numbers every day for long periods of time just from surfing the net, know what I mean?

-Danny 

2012/08/05 10:44:43
Kreative
Yeah, I'm, at about 58-64C just surfing the net. But compared to what it was, this is acceptable, for now. My fan is working and I don't seem to have any other issues that I'm presently aware of. I have not been running temp checks since before this mentioned problem started and have no long term idea of where my temps have been overall.

However, I have read that my current temperature is at an comparably acceptable level. Nevertheless, compared to some of the examples you've provided from other users, mine is running hotter than one might expect for simply doing the Internet. And for some unknown reason, the Internet is my problem, and I don't see the higher numbers when doing DAW work. Perhaps this is still related to the NET Framework service using excessive resources. Yet, it is no longer in an infinite loop persistently trying to start, but never fully able to run. I have to do more checking into dust and other factors, also, since I've never opened up my Vaio to get to the fan, having only shot some compressed air into the fan to alleviate a possible problem.

Check out this article about i7 temps. Very enlightening.  http://www.pugetsystems.com/blog/2 [...] peratures/ 

" Intel Core i7 CPUs have extremely good temperature tolerance. Not only are they made with a Hi-K silicon which is able to withstand higher temperatures, but they have very good power management. There are more transistors dedicated to power management on Core i7 CPUs than there were transistors in the original Pentium Pro CPU! What we’ve found is that the Intel Core i7 CPUs throttle down their speed starting at 100C. So, 100C is the maximum operating temperature of Intel Core i7. However, due to the great power management, we have never seen instability due to temperature. We can run full stress testing at 100C and have no errors. Of course, that’s not a good idea, but my point is that the excellent management features reduce the risk of high temperature. " And here  http://www.cpu-world.com/CPUs/Core [...] QM%29.html  At the bottom of the second link it tells you the max is 100c 
2012/08/05 11:02:28
ohgrant
 To be honest though it can take extreme heat without causing permanent damage I would still say 65C just browsing sure seems too hot to me. Not sure what the core slowdown threshold is on an I7, it use to be 70C on P4 cpu's.  100C and shutting down sounds to me that it is hitting the threshold when just doing minor tasks. I would remove the HS and fan and re-seat them with arctic silver thermal paste
2012/08/05 11:04:08
Jonbouy
FWIW all my .Net Framework services are set to Manual rather than the default Automatic (Delayed Start), they are only loaded in this circumstance when required.

The WPF service is also set to manual here.

My i7 chip runs at around the 30-35 degrees C mark when browsing.
2012/08/05 11:07:05
Kreative
It could be that, when on the Internet, my WPF is just using too many resources and should be set to manual, also. I'll have to look into changing that when I get some more time.
2012/08/05 12:36:58
Kreative
I'm by no means an expert with computer problems, as I only learn the essentials of what I need to know only as I need to know it. I haven't time for much else.

It looks as though my WPF is always running, on or off the Internet, regardless, though it does not show up in the Task Manager processes tab, only under services. And it is now set to manual, though it appears to be running all of the time. This may or may not any longer be a problem for me, since it is no longer  cycling  in an infinite loop [in starting rather than running]. The service status says that it is started, but I do wonder if it should not say instead that it's running.
2012/08/05 12:41:46
Kreative
ohgrant


 I would remove the HS and fan and re-seat them with arctic silver thermal paste

Good advice to be sure this is not a problem. I'm not sure I want to take all of this apart myself, though.
2012/08/05 12:43:30
Kreative


My i7 chip runs at around the 30-35 degrees C mark when browsing.
Mine is still up as high as 64C as I write. Still, its down some 20 degrees below when I was experiencing the WPF loop.

2012/08/05 19:49:25
ohgrant
Kreative


ohgrant


I would remove the HS and fan and re-seat them with arctic silver thermal paste

Good advice to be sure this is not a problem. I'm not sure I want to take all of this apart myself, though.


I can understand that. I've done some reading and I still think your temps are a bit of cause for alarm. Not that any permanent damage is being done, but that close to the core slowdown threshold you can't be getting the maximum performance from your CPU. They start throttling down and only shutdown as a last resort. 
 
12
© 2026 APG vNext Commercial Version 5.1

Use My Existing Forum Account

Use My Social Media Account