File copying speed drops

Meehael

Member
Nov 15, 2011
81
1
71
Hello,

I have two computers in a LAN, both have Win7 64 bit. They're connected through a router. When I want to copy a file (about 2GB) from one comp to another, the copy speed starts at about 10MB/s which is great since I have 100Mbit LAN card, but after about a minute it drops down to about 3MB/s. I tried restarting copying, restarting coputers, but each time after about a minute, the copy speed drops down to 3MB/s. I used windows Resource Monitor to see what is happening, and I noticed that when the copying speed drops, the network begins to fluctuate/oscillate like crazy. Don't know if that is the cause or consequence. No one was downloading anything during the time I tried to copy the file.

I have Intel i3 2120, 4GB DDR3 1333MHz, MSI GeForce 560GTX 1GB, WD 2TB, ASUS P8H61Pro. Avast antivirus, and not many applications or programs installed, just the "essential" ones.

Thank you for your help
 

Ferzerp

Diamond Member
Oct 12, 1999
6,438
107
106
Does your target parhaps have a motherboard managed RAID5 array with no caching?
 

Gunbuster

Diamond Member
Oct 9, 1999
6,852
23
81
This is one single file right? Windows is horrible at large numbers of small files...
 

Meehael

Member
Nov 15, 2011
81
1
71
I tried Teracopy. The results are the same.

I've made some more interesting tests. When I copy from the desktop PC to the laptop, copy rate is great, about 30MB/s, but when I copy from the laptop to the PC, the copy rate is only about 3MB/s. I even tried connecting them directly via network cable, bypassing the router. Results are the same. I have two disks on the PC, one is a system disk 250GB, the other is storage 2TB.

Yes, it's one large file. Don't know about RAID. Never used it. Can I set something in the PC's BIOS?

Thanks
 

Meehael

Member
Nov 15, 2011
81
1
71
I think I found out what was the problem. In BIOS, under SATA Configuration, I set SATA Mode from IDE to AHCI, and now the copy speed is about 12 MB/s the whole time.

Thanks for the ideas!
 

Meehael

Member
Nov 15, 2011
81
1
71
And if I connect them directly (bypassing the router), I get speeds of about 50-100MB/s. Both computers have 1Gbit LAN cards, after all. So, I guess the router was a bottleneck?
 
Last edited:

ViRGE

Elite Member, Moderator Emeritus
Oct 9, 1999
31,516
167
106
And if I connect them directly (bypassing the router), I get speeds of about 50-100MB/s. Both computers have 1Gbit LAN cards, after all. So, I guess the router was a bottleneck?
I'd say so. WAN <-> LAN throughput is always a concern on routers, but some older models have been known to have similarly poor LAN <-> LAN throughput.
 

Meehael

Member
Nov 15, 2011
81
1
71
Maybe this should be a post for hardware section, but I'll continue asking here. I have a Thomson TG782 router and it says that its LAN interface uses "4-port autosensing 10/100Base-T auto-MDI/MDI-X Ethernet switch". From the looks of it, I'd say its top speed is 100Mbps?
 

Weltschmerz

Junior Member
Oct 15, 2012
8
0
0
Try disabling Remote Differential Compression. With this feature enabled, the systems only use the required resources necessary to transfer files across networks, thereby can possibly handicap maximum transfer speed.
To disable this feature, go to Control Panel -> Programs and Features -> Turn Windows features on or off, uncheck Remote Differential Compression and reboot. Disabling this feature does no harm and it might solve your problem. No guarantee though.
 

frowertr

Golden Member
Apr 17, 2010
1,372
41
91
Maybe this should be a post for hardware section, but I'll continue asking here. I have a Thomson TG782 router and it says that its LAN interface uses "4-port autosensing 10/100Base-T auto-MDI/MDI-X Ethernet switch". From the looks of it, I'd say its top speed is 100Mbps?

I'd say you are correct!