Different speeds on two computers plugged into same switch.

I'm puzzled. I have a Dell XPS 8700 that regularly records internet speeds of over 70 down and about 18 up. It's been steady and stable for years.

I also have a Dell Inspiron 3650 plugged into the same switch. It manages a download speed of 25 to 28, and uploads at about 18. I put in a new ethernet card, but nothing changed. The network is all fine and I can move files around at 300-500 Mbps.

I'm completely puzzled. Why should I have such different download speeds? Both computers are capable of utilising a full 80/20 connection but I can't find a setting that's throttling the Inspiron.

Can anyone offer any ideas? I'd be very grateful!

What ethernet NIC did you install into the Inspiron?

Edited by deleted (Mon 01-Oct-18 16:49:52)

Different hardware. I just replaced a laptop I bought in January because it developed a fault. This new one (an
HP ProBook 470 G5 ) is the first one of five or six I've owned that gives the same result for single threaded downloads as for multi-threaded. Three of the others were Acer, the newer failed one was another HP.

All the others have started slow and gradually ramped up to perhaps 75% of max speed on the single thread test. This one jumps pretty much straight up to full speed on both tests. I have no idea what the difference is :-/

Interestingly it also launches Chrome faster (almost instantly) and several web sites like Amazon and Tesco that were sluggish are now absolutely fine. Some of that might be due to it having an SSD though I'm not sure how in the case of slow web sites.

Edited by Andrue (Mon 01-Oct-18 19:09:18)

TP-LINK TG-3468 Gigabit PCI E, which gives the same performance as the original onboard Realtek adaptor.

Have you checked the MTU on both? The slow one may be sending packets that are too large and have to be broken into two?

Yeah, I think sheephouse may be onto something here.

You got me excited there! It's 1500 on both for ipv4, and 1492 for both on ipv6.

Post deleted by RobertoS

Then, yes maybe Andrue is right. I assume you've already checked this, but are both systems are clean e.g. have you tested this with just the OS installed?

Edited by deleted (Tue 02-Oct-18 15:45:34)

I haven't cleaned the systems, but the slow one has very little installed on it. The fast one is heavily laden with all sorts of stuff. I have done all the normal housekeeping on both systems. The slow system can download files over the network very fast - it's just internet download speeds that are poor. So it's not the NIC, I think. More to do with IP stacks and the like.