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10

GigaBIT Ethernet is 1 billion BITS per second. Theoretical maximum transfer is 125MB/sec. Having said that, your 35MB/sec is a bit slow, but encryption is going to slow down SCP file transfers and that probably accounts for it. Encryption aside, any file transfer is a poor network benchmark as your I/O subsystem may be bottlenecking the transfer, though. ...


9

Gigabit is not Gigabyte. The best case transfer speed is 125MB/s (1000 gigabits / 8). SCP is a poor tool to measure bandwidth. You have the overhead of the encryption, you may have compression enabled, and you will have to take into account the speed of the drives on both the source and destination. Iperf is a much better tool to measure bandwidth. If ...


7

Because you are using a gigabit switch (and not a hub) and otherwise all gigabit capable devices and cabling except the firewall, all your devices will communicate with each other at gigabit speeds. Only traffic going to/from or through your firewall will be limited to 100mbps, and likely a lot lower if your internet connection is not 100mbps either, in ...


7

You need to ensure you have a HDMI v1.3 or 1.4 compliant cable to achieve this, even then you'll never see more than 8.16Gbps due to overhead. I've never seen HDMI being used this way, most sysadmins just buy switches with 10Gig ethernet ports to deal with the...erm, 10Gig ethernet. I like the ideal of the HDMI but it sounds a bit fragile a solution (as is ...


7

Duplex is a bit of a misnomer in Gigabit Ethernet as there are not separate send and receive channels like in 10Mb or 100Mb Ethernet. In the lower speeds 2 wires are used to send, and 2 to receive. The other 4 wires aren't used at all (for data anyway). In Gigabit Ethernet all 4 pairs are used to send and receive. It uses a 2 of 5 trellis coding: For ...


6

I am sorry to say, but SOME of the stuff you say makes no sense at all. Really. You pretty much ahve to be a north korean rendering company for it to make sense. 50 PC's connected to the various switches. 20 workstations and 30 render nodes. And: Managed switches are out of the budget Really. You can pay 20 people working, plus all the ...


6

What's the maximum speed of an Ethernet cable (not a phone cable! the one that has 8 threads) Gigabit Ethernet (1000BASE-T) utilising a standard cat5 ethernet cable is cabable of 1,000 Mbit/s (mega bits per second) or 116 MB/s (mega bytes per second), although achieving this is practice can be troublesome, it's almost possible to achieve using two ...


6

In this situation, you won't need to upgrade your firewall. You're correct in that your devices will communicate with each other via the gigE switch. The presence of the 10/100 device won't have an adverse effect on your network.


5

Try disabling Window's auto-tuning feature. In a CMD window: netsh interface tcp set global autotuning=disabled Re-run your test, and see if you notice a performance improvement. I've had to do this on a couple of laptops running Windows 7 in my house, and it's helped. If things get worse, or you don't notice any improvement, you can re-enable ...


5

Transfer speeds will only be as fast as the slowest of the client and recipient system, which is a combination of processor/memory speeds and harddrive access times. SCP also adds a lot of overhead for all the encryption.


5

I've done exactly that with the same, or very similar switches before - no issues. Did you try switching the cables to different ports? Or switching cables? I've seen plenty of broken cables, connectors, and even individual ports. Also, when you say 'Connecting' do you mean they are detecting the cable, the lights on the ports on both server and computer ...


5

In Dell switches it's called Port Mirroring (as opposed to port spanning). Look in the Port Mirroring section of the Ports section in the user manual. http://support.dell.com/support/edocs/network/pc5548/en/UG/PDF/en_ug.pdf


4

afaik 1.25GBit/s is physical layer bit rate; you need to deduct from it error-correction overhead and you get 1Gbit/s of 'usable' bandwidth. [ look here too ]


4

Also, Ethernet seldom gives you your entire line speed. I've very rarely seen a full 125MB/s on a server, and that test was purely synthetic. In real world scenarios I've seen over 100MB/s frequently, and even 120MB/s a time or two. The caveat there is that I was dealing with servers doing disk operations (multiple backup-to-disk streams going to fast Fibre ...


4

In theory it is as simple as you describe. The problem you will run into is that you need to join two pieces of fiber. In practice you have two options for this: Mechanical splicing. You use a special clamp to join the parts togeather. Gives high losses, but considering your short distance it is an alternative. Fusion splicing. You use a large and ...


4

The server's NIC is 1 Gb, the switch is 1 Gb, so the server's NIC will always be connected at 1 Gb. Best case, yes, each 100 Mb client can communicate at 100 Mb to the server. If the other subsystems in the server can keep up - CPU, disk IO, etc.


3

My read of it is that the NAS is the main bottle-neck. 30 nodes pulling the same (presumably large) file is a great way to fully saturate the NAS's network link for anything that hits it. I imagine that as the Render nodes finish they upload their completed work to the NAS which probably causes its own slowdowns as well. An additional bottleneck is probably ...


3

Perhaps you can switch to something like flamethrower, the multicast file distribution program, to prevent you from having to send 60GB (2GB to 30 machines) and instead sends 2GB across the network... If that's not an option, you're probably going to have to upgrade the bottlenecks in your network. From your description, it sounds like the NAS is the ...


3

To verify whether the laptop is not at fault, run up an ubuntu live cd, install iperf onto the ramdisk and run a test. This should at least test the network side of it.


3

Yes, make sure you're getting SPF+ direct connects and that your cards support that configuration. Some exclusions apply. See dealer for complete rules, full details, and restriction. Your millage may vary. Slippery when wet.


3

Typically they would be used for the trunks, either back to a server that most of the ports would be going to so there is extra bandwidth, or to daisy chain multiple switches together. If most of the ports that are 100Mbit go back to a central server a lot, the 10x bandwidth on the trunk means that 10 of those ports can theoretically use that trunk with no ...


3

The router connects you to the internet. Unless you have a 1Gbps internet connection then connecting the 1Gbps ports between the router and the switch isn't going to do you any good.


3

I have not seen a latency or performance impact, but it is a maintenance issue... many of these devices are not managable so you do not get good visibility to link error statistics or (in some really bad cases) you dont even get link down on both sides. I dont want to be all negative, but do think carefully about troubleshooting, rack mounting, error ...


3

There is measurable latency (few ns); it's not noticeable unless your running HPCs or something similar.


3

He's probably referring to hardware vs. software. View from above Yes to a certain point all hardware firewalls are software but given the right hardware you can reprogram the hardware. That is usually quite an expensive operation but once the hardware is reprogrammed the firewall can operate at line speed. Performance in Linux We had a DDOS attack on ...


3

Aria2 is command line tool similair to wget that supports multiple simultaneous downloads over http , bittorent, ftp etc. aria2c -d /dev -o null --allow-overwrite=true -x 15 url --file-allocation=none Would download your file with 15 connections to /dev/null. the allow-overwrite prevents aria from trying to rename /dev/nulll. I prefer not to start ...


2

This seems to be a big issue with Windows 7. Several gamers have complained about this issue. From a command prompt (usually in All Programs -> Accessories -> Command Prompt) run “regedit” Browse to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\Tcpip\Parameters\Interfaces Browse the items under interfaces until you find one that has an IPAddress ...


2

Many manufacturers claim 48Gbps capacity for such switches, but there may still be significant differences in performance. You also need to compare packets/sec capacity and switching latency (if you can even find those specs in product literature). For example, recently I replaced a Netgear JGS524 (24-port gig unmanaged) with a Cisco 2960G-24 in an iSCSI ...


2

I would try booting the Windows machine with a bootable Linux CD like Ubuntu, and check the statistics there, to exclude the possible Hardware issues.


2

Great answers from the others here. You should have enough there to give you all the ideas you need. However, here's a couple of thoughts from outside the box: Set up a local bit-torrent tracker on your network (visible ONLY to your network), and share your large files among your workstations via bittorrent. Does every render station need the entirety of ...



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