Group shot.
The DGS-1008D switch.
Size.
D-Link Gigabit Ethernet Networking Products Review
Date : Tuesday, 10 August 2004
By : Stygian
Provided By : D-Link
Introduction
With all the attention wireless networking is getting nowadays, not just from computer magazines and Internet sites, but also from mainstream media outlets, you'd think that wired networks were dead - however, this is far from the truth. While wireless networking has undoubtedly become a driving force in the networking market, it's far from perfect as there are certain inherent security issues that aren't easily resolved. Adding to that, wireless networking is still not as fast even the most common wired networks out there, despite marketing claims to the contrary. These factors, amongst others, have given incentive for many to remain to their wired networks.
While wireless networks are certainly more convenient for mobile users - those with laptops/notebooks, PDAs and other wireless devices - they offer little advantage to desktop computers that are already tied down due to their weight and attached peripherals, other than perhaps removing the need to do a cable run. In fact, many people have already set up their house for a wired network, and have the physical capability already built in; for these people, switching to a wireless network as an upgrade may present more problems than benefits. So what are these people to do if they're looking to upgrade their network?
Enter Gigabit Ethernet, or 1000BASE-T. Poised as the successor to the nearly-omnipresent 100BASE-T, it offers a theoretical maximum transfer rate of 1000Mbps, as its name implies. The great thing about it is that devices that adhere to this specification are meant to work over existing CAT-5 cabling, as long as they have four pairs of wires, which most CAT-5 cabling has. (Even though the 100BASE-TX implementation only uses two of these pairs) So, an upgrade path is easy; all one has to do is change out the old network adapters for Gigabit ones, and swap old switches for Gigabit ones. Additionally, the Gigabit devices are backward-compatible with 10/100Mbps network adapters, as you would expect them to be - so not only is the upgrade path easy, but it is painless as well - one need not upgrade everything at once if this isn't a viable option.
With nearly every office wired with CAT-5 nowadays, Gigabit Ethernet is the best upgrade option; it's not meant as a replacement for wireless networking, of course, as the two appeal to different segments. However, Gigabit Ethernet has been somewhat overlooked in the recent past due the hype surrounding wireless networking, but the need for fast wired networking is as real as ever. However, the industry hasn't been blinded, as many motherboards now come with onboard 1000BASE-T network adapters built in; Intel's 875P chipset with its CSA bus is a good example.
D-Link also hasn't been complacent, as they have a whole line of Gigabit products, most targeted at the business/Enterprise side of things; but they also have some products for the SOHO environment. Today, I'll be looking at their DGS-1008D 8-port Gigabit Switch, and their DGE-530T PCI Network Adapter, to see if Gigabit Ethernet provides tangible benefits over the widely installed 100Base-T networks, and to see if upgrading is worth it.
Specifications
Both the switch and PCI network adapters are fully backward compatible with 100BASE-T and 10BASE-T parts, so you won't have to upgrade everything in your network at once; of course they full support 802.3ab Gigabit Ethernet, and so they should interoperate nicely with other devices that also support this standard; all you need to do is supply the CAT-5 cables.
Common specs:
Some other notable features are a five-year warranty on the switch, and a limited lifetime warranty for the PCI network adapter. Though it's not too often that such equipment fails, it's nice to have such a good guarantee. Additionally, the switch's ports are all auto-sensing/switching between MDI/MDI-X; this means that you no longer have to worry about having the right type of CAT-5 cable (either a straight-through or a cross-over) when connecting other devices to a port on this switch; this auto cross capability greatly simplifies setting your network, as you'll no longer have to go run out and buy a cross-over cable just to connect one other type of networking device since the auto cross feature will automatically adjust its circuitry depending on the type of cable/device attached. Most newer switches feature this capability, so it's nice to see this available.
The D-Link products look unassuming in their fairly modest packaging. Like most of D-Link's other SOHO products, both the switch and PCI adapters come well-packaged. The switch in particular bears no distinguishing marks other than perhaps its model number and other few labels that adorn its front. Beyond that, it has the same grey/blue colour scheme of most other D-Link products that you may have seen; I guess it's all part of trying to make their products all have the same look and feel so that people will recognize the D-Link brand. This can be a good or bad thing, depending on the quality of your products. The box claims "Up to 100x faster" than Ethernet - they are of course referring to the hard numbers involved when comparing 10Base-T and 1000Base-T; not many people use 10Base-T networks right now, and even so, you'd be hard-pressed to find someone who would agree that the performance increase would be 100X faster in the real world. Besides the switch itself, the package also includes a small manual, the 5VDC adapter, and a bag of mounting hardware. No CAT-5 cables were included, but with 8 ports, it'd be kind of ridiculous to expect D-Link to include one for each of them.
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Group shot. |
The DGS-1008D switch. |
Size. |
The switch feels fairly light, due to its plastic body construction; though I would've liked a metal body, rarely are home networking devices built with such materials. While such a construction would've made the switch feel more strong and stable, it didn't feel loose or cheap. My only concern with the light weight would be that if this switch were placed near the edge of a surface with many cables plugged into it, there could be a possibility of the cables pulling the switch off in one direction. This shouldn't be an issue however, if you are careful. As mentioned before, the switch resembles other D-Link products and if you have one, you'll know exactly what I mean. The switch is a bit bigger than most others though, since it has 8 ports; however it is not unduly large and should fit in most places. The switch can be stacked, and includes little "feet plugs" that seemingly allow two D-Link switches to attach to one another in a secure stack. However, D-Link recommends that if you do stack this switch, it should be placed on top of the stack for proper ventilation and cooling. Additionally, mounting hardware was included so this switch could be placed on a wall if you were willing to make some holes for screws.
 Front. |
 Back. |
 Bottom - mounting holes can be seen. |
On the front, there are LEDs for power and Link/Act for each port, as you would expect. The back is where the RJ-45 jacks are, as well as the power connector. As this is an unmanaged layer-2 device, there's no need for a reset switch. However, a switch is undoubtedly better than a hub for a network since being a layer-2 aware device, it "knows" what MAC addresses are attached to what ports; thus when transmitting frames, from one computer to another, only frames whose destination MAC address matches a list of known attached MAC addresses is sent out through that port, thus reducing the amount of "unnecessary" network traffic.
The PCI adapter resembles any other NIC I've seen; it's a low-profile card and D-Link has also included a bracket that'll allow you to install this NIC into a slim Micro-ATX type enclosure, whose height is less than that of most cases. (Low profile adapter) Included beyond this are a short manual, and the driver CD; not much, but pretty standard fare. The card has 4 status LEDs: Link/Act, Full, 1000M, 100M, and the included manual, while shorter and more spartan than the usual D-Link fare, is more than enough since there's not much involved with installing this NIC.
 The DGE-530T Gigabit PCI Network Adapter. |
 Looks normal. |
Both the switch and this NIC support full duplex modes of operation, so the adapter can send and receive at full speed. Like the switch, this card is fully backward compatible with other forms of Ethernet, so if you just install this NIC, it'll work with existing hubs/switches out there that may not support 1000Base-T; of course, it'll just switch its mode of transmission to match the hub/switch so you won't get full performance out of it. This makes the card an easy upgrade solution, since things will be seamless, but makes it kind of pointless, from a practical standpoint, to upgrade; hence you'll want to have your switch upgraded as well if you get one of these NICs. Other notable features are Wake-On-LAN support, (if you're into that sort of thing), network management via SNMPv1, and a Cable Diagnostics utility for Windows; however, the average user is not likely to use these features. Having said that, let's get on to the important part of installation and testing.
Installation
As you can imagine, installation was a breeze; there's no complicated settings to mess with like the SSID, WEP Keys, channel, etc., since these are wired network adapters. All that I needed to do was shutdown, remove the old network adapter (a Linksys LNE100TX v2.0 from like 1999), install the new D-Link Gigabit adapter, and then power up the PC. Then when Windows XP booted up, I just had to insert the included driver CD and point to the directory with the drivers on it; Windows installed the drivers (v6.23) fine and without a reboot, the PC was ready to go.
 Woohoo, Gigabit!. |
 The D-Link DGE-530T's option. |
Some considerations to note relate to Ethernet specifications; just like before, cable length is limited to 100m. (Without using a device such as a repeater) Additionally, you may want to keep your CAT-5 cables away from strong sources of electrical interference. Installation of the switch involved... plugging the power in and then plugging end stations into it. That's it; there's not much to say unless you want to talk about the topology issues, which are pretty boring. All you need to know is that a switch is better than a regular hub (which you don't see in many consumer SOHO products anymore) since it segments whatever's connected to each of its ports; hence traffic from one segment to another only goes between the two and thus this reduces network usage leading to higher performance.
Another more important issue revolves around the fact that this is a PCI Network Adapter, and hence, will ultimately be limited to the performance of the PCI bus. If you look at the hard numbers, 1000Base-T is spec'd to provide a 1000Mbps data rate; this roughly translates into 125MB/s or 119MB/s depending on what you view as a "Megabyte". The PCI bus is spec'd to provide a 133MB/s data rate. As you can see, these two numbers are very close, leaving little apparent room for other PCI devices. However, this isn't the full story as first you'll note that not many storage solutions can read, much less write, at a sustained speed of 119MB/s! And, of course, all the layers of networking specifications take up some bandwidth to provide things like addressing schemes and other meta-information, thus reducing the effective data rate of a network far below its spec'd rate.
However, many in the industry have taken note of this bandwidth discrepancy, and have taken action; for example, some of Intel's chipset support the CSA bus, a direct link to the North Bridge that was meant for use with onboard Gigabit Ethernet Adapters; thus the network traffic doesn't ride the PCI bus, freeing up its bandwidth for other devices such as perhaps a soundcard, or a SCSI card. At the same time, it's worthy to note that most chipsets nowadays have moved most stuff such as SATA and EIDE controllers and USB ports off of the PCI bus and given them a direct link to the South Bridge, also reducing reliance on PCI bandwidth.
Testing
As we all know, numbers don't usually tell the truth; going by pure numbers alone, Gigabit Ethernet would have to be 10 times faster than my current setup, but often other factors are present that reduce the overall performance. I tested the D-Link equipment both using Ixia's QCheck Program, a bandwidth-checking program, and by doing a file transfer test of 300MB of files. I first tested 100Base-T performance by leaving my current Linksys LNE100TX v2.0 adapters in and connecting the two computers through D-Link's DGS-1008D Gigabit Switch; since both cards only supported 100Base-T the speed would be limited to this spec. I then upgraded both PCs to the D-Link DGE-530T Gigabit adapters, and again plugged them into D-Link's Gigabit switch for testing. At both times, the only devices attached to the switch were the two test stations.
Here's what I found: D-Link's Gigabit Ethernet is undoubtedly faster than Fast Ethernet, but not many, many times faster. Response time was unaffected, as you might have expected, as both tests reported a < 1ms response time at all times.
As you can see, in the synthetic bandwidth test Gigabit Ethernet showed a 3x improvement over Fast Ethernet. This is impressive, but what does it mean in real-world terms? I mean, for most everyday things, 100Base-T is plenty fast enough. I decided to do a file transfer test by transferring about 300MB of files several times between the two computers and timing each test. Here are the results:
As you can see, the Gigabit setup averaged about 25s per test, while my old network setup could only muster a 42s time. While this is a great improvement, it isn't a 3x faster improvement. I think the decrease in actual performance may have come from the fact that other devices were using the PCI bus at the same time the network card was, thus reducing overall performance. However, this speed takes the cake as far as I'm concerned, as it's the fastest I've ever seen, and if you're used to wireless networking speeds now, these speeds will be a godsend.
Just for reference, I used the QCheck program to do a localhost-to-localhost TCP bandwidth check, to test the "speed" when the network wasn't involved. At all times, I got a data rate of 727Mbps - this should give you an idea of the other limiting factors that decrease the overall speed of a solution.
Conclusion
Going by the results, the D-Link Gigabit equipment is certainly an improvement over 100Base-T. Reducing the file transfer time of 300MB of files by 17s is no small wonder, and thus you're guaranteed increases in performance. What I'm more concerned with is the actual noticeable improvements to the end user. Certainly, when going from a wireless network to a wired one, most people would notice the speed increase, since large file transfers over wireless networks are usually an agonizingly slow process. However, in going from 100Base-T to 1000Base-T, how much of the performance increase will we notice? In a SOHO environment, or one where large file/data transfers aren't too common, the performance increase noted may be minimal. However, I do believe these products have a use; if you truly use your network to its maximum capacity and have a "wired" house with many connected devices, these D-Link products will do much improve your network's performance. If nothing, the 8-port switch is a great upgrade over any hub you may have, and you'll notice the difference immediately. If however, all you do is browse the Internet through one or two computers, these products probably aren't for you.
Pros
Cons
Finally, I'd like to extend a big thanks to D-Link for making this review possible!