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I am looking for ways to bump up the transfer speed between my local computers on my home network. I have 3 desktop computers and they are all running Windows. One uses wired connection and the other two are using wireless connection.
Desktop 1
- Wired connection
- 100 Mbps NIC (integrated, Realtek)
- Cable type is Cat 5e
- Cable length is < 20 meters
- Windows Vista
Desktop 2
- Wireless connection
- 300 Mbps NIC (USB 2.0, D-Link DWA-160 dual-band @ 5 GHz, Atheros chipset)
- 1000 Mbps NIC (integrated, Realtek, not in use)
- 1000 Mbps NIC (integrated, Realtek, not in use)
- Proximity to router is < 10 meters
- Windows Vista
Desktop 3
- Wireless connection
- 300 Mbps NIC (USB 2.0, D-Link DWA-160 dual-band @ 5 GHz, Ralink chipset)
- 1000 Mbps NIC (integrated, Realtek, not in use)
- Proximity to router is < 20 meters
- Windows 8
Router
- D-Link DIR-825
- Wireless N
- 1000 Mbps integrated switch
- Both 2.4 and 5 GHz bands are enabled
- DD-WRT firmware
- WPA2/AES encryption mode
I have a 10 Mbps dedicated Fiber-LAN connection to the Internet. That's exactly 1.25 MB/s. I can achieve this speed when I download something from the web, and beyond that. I can easily download at 1.3 MB/s from either one of the computers. I can upload with the same speed, and usually exceed that and peak out at about 1.7 MB/s.
Now, when I transfer a 250 MB file between two computers locally I can only get about 3 MB/s on average. How can I bump this up to at least 12.5 MB/s? As you can see, two computers are Gigabit-Ethernet capable, and one is only Fast-Ethernet capable. If they all operate at the slowest speed available, that would be 100 Mbps. I understand that this is only theoretical speed. But what's preventing me from achieving at least half of that? That would be 12.5 MB/s, and I would be happy with that.
Note that MB/s != Mb/s. One megabyte (MB) is eight megabits (Mb) per second. – Blacklight Shining – 2013-10-14T20:52:20.900
1@BlacklightShining Yes, thank you for clarifying that. Let me just add that I am not mistaken. I know for sure I have slow transfer speed locally. I understand the difference in bits and bytes. I just don't like using the slash, e.g. "MB/s" so I use "MBps". Note the upper-case B. – Samir – 2013-10-14T20:54:19.577
You might want to convert everything to one or the other, to avoid confusion. (IMO, everything should be done in mebibits (MiB)—they're based on powers of two rather than powers of ten.) – Blacklight Shining – 2013-10-14T20:58:27.543
Your router may not be able to process data faster than the speeds you're seeing. Try just a cable between two PCs and see how fast it transfers. – Ƭᴇcʜιᴇ007 – 2013-10-14T21:06:43.373
possible duplicate of Why transfer speed over Fast Ethernet (100mbps I think) is only ~1.5MiB/s
– Synetech – 2013-10-14T21:11:48.597@BlacklightShining, Sammy already accounted for units from the start, so that is not a point of confusion. – Synetech – 2013-10-14T21:12:38.757
@BlacklightShining Right! So how many "mebibits" per second is 10 "megabits" per second? I am using the units as they appear on network equipment and inside Windows. I have added the slash for MB per second. You won't confuse it with Mbps now. – Samir – 2013-10-14T21:12:50.570
@Sammy, I recently wondered about this issue. I transferred some files between two systems through my router and was confounded that they were limited to 1.5MBps (the meter showed a peak of 1.7, but it was 1.5 on average). While researching the issue, I found Jiew Meng’s question and considered editing it to provide more information instead of opening what would amount to a duplicate question. Then I saw your question which is the same. It seems this is not a defect, but a limitation of something. Hopefully we can find a solution or work-around.
– Synetech – 2013-10-14T21:17:22.0232When you transfer a file between two wireless machines, all the data has to be sent over the wireless link twice, once from the source to the access point and once from the access point to the destination. The acknowledgements have to use the same channel, and it takes time to "turn the channel around" when a device switches from transmitting to receiving. Take your 100Mbps (which is likely roughly your effective WiFi bandwidth as well) and divided it by 3 to account for these costs and you get about 4.2MB/s -- your expectations are unrealistic. If possible, wire all devices. – David Schwartz – 2013-10-14T21:41:49.173
@DavidSchwartz Would it help to add a dedicated switch into the mix? Instead of using the built-in switch of the router? I'm thinking maybe the router can't process the data fast enough, locally, as opposed to externally (WAN throughput). I think you have touched on that here. So I was thinking maybe a separate AP and a dedicated switch behind the router and the Internet connection? Is it worth it? Or would that be just adding pancake on top of another pancake? I mean a wireless router should already have this capability. – Samir – 2013-10-14T21:52:59.500
@Sammy How could adding an extra hop possibly help? You would then have to go from the router's WiFi to the router's CPU to the router's switch (to get to the router's Ethernet port) to the external switch ... That would be very slightly worse. The router has a hardware switch between its Ethernet ports. If it's router load, it's with the WiFi-to-switch part, not the switching itself. – David Schwartz – 2013-10-14T22:02:28.590
When you transfer a file between two wireless machines… take your 100Mbps (which is likely roughly your effective WiFi bandwidth as well) and divided it by 3 to account for these costs and you get about 4.2MB/s
Already considered that; it doesn’t explain it. I transferred between one wired and one wireless. Even dividing 54Mbps (802.11g) by three still gives 2.25MBps, not 1.5. Something else is “bottlenecking”. – Synetech – 2013-10-14T22:13:44.647