Gigabit Ethernet: Dude, Where's My Bandwidth?

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Test Systems

Server SystemClient System
CPUIntel Core 2 Duo E6750 (Conroe),2.66 GHz, FSB-1333, 4 MB CacheIntel Core 2 Quad Q6600 (Kentsfield),2.7 GHz, FSB-1200, 8 MB Cache
MotherboardASUS P5K Intel P35, BIOS 0902MSI P7N SLI Platinum Nvidia nForce 750i, BIOS A2
NetworkingOn-Board Abit Gigabit LAN controllerOn-Board nForce 750i Gigabit Ethernet
MemoryWintec Ampo PC2-6400 2x 2,048 MB, DDR2-667, CL 5-5-5-15 at 1.8 VA-Data EXTREME DDR2 800+ 2x 2,048 MB, DDR2-800, CL 5-5-5-18 at 1.8 V
GraphicsASUS GeForce GTS 250 Dark Knight1 GB GDDR3-2200738 MHz GPU, 1,836 MHz shaderMSI GTX260 Lightning1792 MB GDDR3-1998590 MHz GPU, 1,296 MHz shader
Hard Drive 1Seagate Barracuda ST3320620AS 320 GB, 7200 RPM, 16 MB Cache, SATA 300Western Digital Caviar WD50 00AAJS-00YFA, 500 GB, 7200 RPM, 8 MB cache, SATA 3.0 GB/s
Hard Drive 22x Hitachi Deskstar 0A-38016 in RAID 1 7,200 RPM, 16 MB Cache SATA 3.0 Gb/sWestern Digital Caviar WD50 00AAJS-00YFA, 500 GB, 7200 RPM, 8 MB cache, SATA 3.0 GB/s
PowerAerocool Zerodba 620w620 W, ATX12V 2.02Ultra HE1000X ATX 2.2, 1000W
Network SwitchD-Link DGS-1008D8-Port 10/100/1000 Unmanaged Gigabit Desktop Switch
Software and Drivers
Operating SystemMicrosoft Windows Vista Ultimate 32-bit 6.0.6001, SP1
DirectX versionDirectX 10
Graphics DriverNvidia GeForce 185.85
Benchmarks and Software
Nodesoft DiskbenchVersion: 2.5.0.5, file Copy, Creation, Read, and Batch Benchmark
SiSoftware Sandra 2009 SP3Version 2009.4.15.92, CPU Test = CPU Arithmetic / Multimedia, Memory Test = Bandwidth Benchmark
Don Woligroski
125 Comments Comment from the forums
  • gwiz1987
    why is the RAM-to-RAM network max speed on the graph 111.2 when u state 111.4? typo?
    Reply
  • drtebi
    Interesting article, thank you. I wonder how a hardware based RAID 5 would perform on a gigabit network compared to a RAID 1?
    Reply
  • Hello

    Thanks for the article. But I would like to ask how is the transfer speed measured. If it is just the (size of the file)/(a time needed for a tranfer) you are probably comsuming all the bandwith, beacuse you have to count in all the control part of the data packet (ethernet header, IP headrer, TCP header...)

    Blake
    Reply
  • jankee
    The article does not make any sense and created from an rookie. Remember you will not see a big difference when transfer small amount of data due to some transfer negotiating between network. Try to transfer some 8GB file or folder across, you then see the difference. The same concept like you are trying to race between a honda civic and a ferrari just in a distance of 20 feet away.

    Hope this is cleared out.
    Reply
  • spectrewind
    Don Woligroski has some incorrect information, which invalidates this whole article. He should be writing about hard drives and mainboard bus information transfers. This article is entirely misleading.

    For example: "Cat 5e cables are only certified for 100 ft. lengths"
    This is incorrect. 100 meters (or 328 feet) maximum official segment length.

    Did I miss the section on MTU and data frame sizes. Segment? Jumbo frames? 1500 vs. 9000 for consumer devices? Fragmentation? TIA/EIA? These words and terms should have occurred in this article, but were omitted.

    Worthless writing. THG *used* to be better than this.
    Reply
  • IronRyan21
    There is a common misconception out there that gigabit networks require Category 5e class cable, but actually, even the older Cat 5 cable is gigabit-capable.

    Really? I thought Cat 5 wasn't gigabit capable? In fact cat 6 was the only way to go gigabit.
    Reply
  • cg0def
    why didn't you test SSD performance? It's quite a hot topic and I'm sure a lot of people would like to know if it will in fact improve network performance. I can venture a guess but it'll be entirely theoretical.
    Reply
  • MartenKL
    Gbit is actually 10^9 bits per second, ie about 119 MB/s.
    Reply
  • flinxsl
    do you have any engineers on your staff that understand how this stuff works?? when you transfer some bits of data over a network, you don't just shoot the bits directly, they are sent in something called packets. Each packet contains control bits as overhead, which count toward the 125 Mbps limit, but don't count as data bits.

    11% loss due to negotiation and overhead on a network link is about ballpark for a home test.
    Reply
  • jankee
    After carefully read the article. I believe this is not a tech review, just a concern from a newbie because he does not understand much about all external factor of data transfer. All his simple thought is 1000 is ten time of 100 Mbs and expect have to be 10 time faster.

    Anyway, many difference factors will affect the transfer speed. The most accurate test need to use Ram Drive and have to use powerful machines to illuminate the machine bottle neck factor out.

    Reply