My PC is slow, jittery sound/video, whenever I download stuff.

[KhronoS]

Lately my computer runs slow, very jittery sound, and video, my mouse cursor jumps, writing stuff is slow having like 1sec lag until letters appear. All of this is consistent ONLY when downloading with speeds about 1mbps.
This is what i noticed:
- CPU never goes over 10%, unless there are really high speeds like 20+mbps, when PC feels like it has completely frozen, and the cpu goes to about 60%.
- The only process that stats to increase in CPU usage is the "System and Compressed Memory"
- HDD read/writes never gets over 10-15%.
- RAM never goes over 60%;
- doesn't matter the type of download, as loong as there is network transfer(youtube video, loading a page, downloading software, torrents, updates)

There's one thing that seams to have some sort of influence: I have enabled Intel Virtualization Technology (VT-x) as I am a developer using a Vagrant and Virtual box to run a virtual machine. Disabling VT-x in bios, it seams to fix it, or maybe it is because of the restart i dont know. BUt i need VTX because as i said, i need to work on my PC.

My computer specs are:
- Intel Core i7-4790K 4.00GHz (Devil's Canyon) Socket LGA1150 Processor
- Gigabyte GeForce GTX 770 WindForce 3x OC 4096MB GDDR5 PCI-Express Graphics Card
- Asus Maximus VII Hero Intel Z97 (Socket 1150) DDR3 ATX Motherboard
- Kingston HyperX 16GB (2x8GB) PC3-17100C11 2133MHz Dual Channel Kit - BlackGold
- Corsair RM Series RM 850 '80+ Gold' 850W Power Supply
- Samsung 840 EVO 250GB 2.5 inch Basic SATA Solid State Drive

I would be really greatful if anyone can help me!
Thank you!
Constantin Chirila

 

[jannikn]

Try using Windows to repair your HDD, if that does not work, you might need a new harddisk.

 

[Colif]

Update chipset/USB drivers, check you have latest bios

Turn power options to high performance, set screen to always be on as well as pc always on, go into advanced options and set hdd to always be on.

 

[KhronoS]

@jannikn I will give it another go. But can't see why HDD could be to blame. Considering that if copy files on the hdd, doesnt slow my system, only when i download, it is very close related to the network activity.

Another update, i tried DPC Latency checker, and it seams that disabling the network card, bring the graph from RED (which is bad) to yellow, which is okish.

Restarting the machine completely fixes it, and cannot reproduce the problem anymore. Also when i download "System and Compressed Memory" doesnt appear in the processes anymore. Hmm...

 

[KhronoS]

Update chipset/USB drivers, check you have latest bios

Turn power options to high performance, set screen to always be on as well as pc always on, go into advanced options and set hdd to always be on.

Bios was updated.
Turned the power settings, i didnt fix it, but i would imagine it would need a restarts, so i will see, as now it seams to work.

 

[Colif]

jittery behaviour is normally sound cards/usb drivers or power... its why I suggested it

 

[KhronoS]

Sooo nothing worked!
After a few more tests the issue seams to be with the Network Driver INterface Specification and the TCP/IF driver, having well above 20ms highest execution latency, and from my research it shouldnt pass 1ms.
Hence the stuttering when i download stuff. I updated the network driver to no avail.
Also disabling my Enthernet Connection fixes the issue. So it's definitly something wrong there, because as soon as i enable it the DPC is back into red zone.

Any thoughts?