Gigabit Ethernet

I've been busy doing some mini projects at home and one of them was to install gigabit switch and NICs in all my computers, except my laptop. So what pushed me in upgrading my home network to gigabit? Well, I realized that moving over 250GB worth of data takes a long time! - obviously. I had to move that much data over my network to my File/Domain/DNS server - running Windows Server 2003. I know, it may be overkill to be running a NOS (Network Operating System) in my home network since it is pretty small, but has its benefits over peer-to-peer networking, which by the way been using since 2000. Moving to a domain-based network has been in my mind since 2002 or 2003. However, I didn't have time to study how to set it up properly since the last time I've touched NOS was back when NT Server 4.0 and it was the de facto standard. Anyway, let's skip all the stories and move to our main topic.

You probably already know this, but let's make this post for non-techy people out there. In order to get gigabit speeds (1000 Megabits per second or Mbps for short - also known as 1Gbps), you need gigabit capable switch (Netgear GS605 - this is what I have), gigabit capable NIC (Network Interface Card) - Rosewill RC-400 - this is what I have, CAT 5e or CAT 6 (recommended). Don't you think it's a little weird that I don't have Cisco/Linksys at home since I work on Cisco routers and switches every day at work? Well, to be honest, I wasn't happy with the very first Wi-Fi router that I bought from Linksys/Cisco. It kept dropping my wireless connection so I had to return it get the brand that I was already familiar with, which was Netgear. The very first Netgear products that I bought were NICs and a 4-port hub. This was back in 2000 which at that time I didn't know anything about networking, so I picked the hub instead of a switch. Well, to be honest, I still don't know anything about networking! c",)

Before we dive in to the network performance of gigabit, I want to show you what the throughput of 100Mbps that I was getting. By the way, I am using FreeMeter as my bandwidth monitor. Below is a screenshot of the throughput using 100Mbps LAN using 6GB file:

The left graph is the upload throughput using 100 Mbps. As you can see, you are not getting the theoretical bandwidth. That is understandable because you'll never get the theoretical bandwidth ever. Why? One notable reason is interference. Attenuation is another one, but it isn't applicable here since I only have 7 feet CAT6 cable.

The right graph is the download throughput using 100 Mbps. 77.1 Mbps was the highest that I could get with my 100 Mbps NIC connected to the gigabit switch. At least it is a little bit higher than the upload speed.

Here's what you've been waiting for, the network performance of Gigabit Ethernet. I am using the same setup with the exception of the NIC - of course. Below is the screenshot of gigabit throughput:

This time, the graphs were switched, but the color remained the same - green for download and red for upload. As you can see, it gave us about 100 Mbps more throughput compared to the 100 Mbps results. But, with the upload speed, it gave us about 200 Mbps more! I seriously wasn't expecting that - I was expecting that I'll get more out of the download than the upload.

Before I purchased my NICs, I read through all the user reviews because I was wondering how much faster if I go with gigabit ethernet. I was hoping to get at least 50% of the theoretical bandwidth, but I guess I was asking too much with the result above - a little disappointing. Anyway, after reading much reviews, I learned something new which was never in any of my books. In all the networking books that I've read, they talk about MTU (Maximum Transmission Unit) size of Ethernet is 1500 octects/bytes. With gigabit, you can use more than 1500 bytes, which they call jumbo frame. According to those reviews that I've read, enabling jumbo frame will give you more throughput - so I had to try.

Last night, I've installed the gigabit NICs in two of my computers (my HTPC has an onboard gigabit NIC, which is good) and I have one more gigabit NIC to install. Anyway, this morning, I changed the configuration of the NIC to 7K jumbo frame. Unfortunately, since I went with a cheap NIC, it can only support 7K jumbo frame instead of the de facto standard 9K jumbo frame. To change the configuration of your NIC, you have to go to the Device Manager. There are two ways to get there, one method is by right clicking My Computer > Properties > *System Properties* will show up > Hardware tab > Device Manager. The second way, which is my favorite, is by clicking Start > Run > type "devmgmt.msc" - without the quotation marks of course. Here's a sample shot of what you'll see:

Once you're there, click on the "+" sign right next to Network adapters. If you have two NICs, you'll see both of them there but pay attention to the right network adapter. In my case, I am using the Realtek based NIC. Oh so you noticed eh? Yes, all of my PCs are named after the characters in Starcraft. Anyway, once you picked the correct NIC, you'll need to hit right click and click on Properties. What you'll see is similar to the one below:

If your NIC supports Jumbo Frame, then you should be able to see it, just like the one above. As mentioned earlier, my NIC only supports up to 7K MTU size - the de facto standard is 9K MTU size. Without further delay, the screenshot below is the network performance with 7K MTU jumbo frame:

Same as before, green graph is for download and red graph for upload. Noticed something? It nearly doubled my download speed! While, the upload throughput went down by about 50 Mbps - a little disappointing. The saying is true, you can't get everything you want! c",)

Just to give you guys a heads up, you may want to read up more on jumbo frame with a mixed node setup. According to what I've read, you'll see problems once you start moving data from 100 Mbps enabled device to a 1 Gbps enabled device or vice versa with jumbo frames. It makes sense because one device can only support 1500 bytes of frame, while the other one is sending out 9KB of frame. I'll give you guys an update once I test it.

Written by: Andr01d

"I know nothing except the fact of my ignorance" - Socrates