Netgear Gigabit NIC...Should I Use it?

Clocker

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My Tyan Tiger MPX board will arrive on Monday :)

I bought this Netgear GA620T gigabit 64-bit/66mhz NIC in anticipation of buying an MPX board w/o onboard LAN but I ended up getting the Tiger MPX anyway. Nonetheless, I have this NIC and it looks COOL. Never had a NIC with THREE heatsinks on it before :) If I didn't have onboard LAN, I would not have had enough PCI slots for all my devices w/o using a 64-bit NIC. But now that I have the Tiger MPX, it isn't really a big concern...

ANyway, should I use this Netgear NIC or just use the onboard 3Com? I think they both will work equally well but the 'cool' factor keeps jumping in there.

I got a great deal on that GA620T NIC btw...ONLY $35 in Anandtech's forums!! It goes for about $290 on pricewatch...

ga620t.jpg
 

Clocker

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Actually, I already have the NIC in my posession. It is indeed very cool looking!!

THe only problem with it is that I need a cable/dsl router that supports 10/100/1000. Either that or I guess I connect the gigaswitch to a port on my router so my two machines can talk over gig-E. Of course, I still need to get another great deal on another gig-E card...

C
 

i

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Two things:

1) Yes, the card might be cheap, but finding a cheap switch or hub that supports gigabit rates through more than one port is going to be very tough.

2) Yes, that card you're looking at is rated for gigabit transfer rates, but let's face it ... you get what you pay for. How often will the card actually reach 1 Gb/s? Just once in a while? Ever? There are a bunch of factors that come into play too ... not just the card's hardware.

Here's why I mention point number 2:

http://www.cs.uni.edu/~gray/gig-over-copper/

(Look Mercutio! I actually remembered where I'd seen an article online!)

The revelation that these cheap gigabit cards don't really do 10x better than the traditional 100 Mb/s has really damped down my interest in them for now. As far as point number 1 goes, yes that kind of sucks too, but I do occasionally have direct connections between PCs. I believe a Cat 5e or 6 crossover cable would actually qualify as a cheap, two port hub (albeit a passive one). :wink:
 

i

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Ahh heck. Tyan MPX ... that does have 64-bit slots, doesn't it? Well, I'll just go crawl back under a rock then. I think one of the points the article mentioned was that performance was typically a lot better if you were able to use 64-bit cards in 64-bit slots. Point number 2 still holds valid for people like myself who can't afford to upgrade yet ...

At least I don't have any ISA cards in this system.
 

Pradeep

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Handruin said:
That looks sweet as far as "cool" factor is conserned. You can't beat the price, why not get it! :) Is there something wrong with it, why is it so cheap?

What are you going to use it for anyway? I think linksys, maybe even netgear has affordable 10/100/1000 switches.

http://www.linksys.com/Products/product.asp?grid=29&prid=192

$115 at http://www.us.buy.com/retail/product.asp?sku=10296762&loc=101&queryType=compbuy.com[/url


That is a 1 gigabit + 8 * 10/100 port switch Doug, the true gigabit switches which have all gigabit ports are a bit more costly.
 

Stereodude

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You need a Netgear GS504T or a GS508T switch. The first has 4 ports of 10/100/1000. The latter has 8 ports of 10/100/1000. Prices are about $600 for the 4 port model and $700 for the 8 port.

Dell has sold some 8 port models for around $400 if I recall correctly.

Stereodude
 

Handruin

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I would use it, but in my apartment it wouldn't help me much. Maybe for the next time I throw a LAN party I can make a machine a dedicated server and buy that linksys. :)
 

Mercutio

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Finding cable that's up to snuff for gigabit is really, really hard. Sure, most anything "premium" you buy will say Cat5e or even "cat6" (not actually a standard yet). The proof is in the transfer rates. Use a crappy cable and they hover around 150 or 200MBit/sec Find the right one and they'll basically skyrocket.

You won't get 10x speed over copper. 4x is very attainable, though.
 

cas

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Mercutio said:
4x is very attainable, though.
Maybe not 10x just yet, but 8x is not unreasonable.

As described here, I have measured 90.5MB/s over copper, with an mtu of 1500 octets. That usable data, after the overhead, with dirt cheap NICs.
 

P5-133XL

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cas said:
Mercutio said:
4x is very attainable, though.
Maybe not 10x just yet, but 8x is not unreasonable.

As described here, I have measured 90.5MB/s over copper, with an mtu of 1500 octets. That usable data, after the overhead, with dirt cheap NICs.

I've been studying the Gigabyte standard and I don't see how you can get much more than 4x using half duplex copper. The reason why is that the GB standard takes standard ethernet frames that are a max of 1522 bytes long and adds filler (the standard call this a carrier extension) to the end to make them 4096 bytes long. The filler's purpose is to increase the slot-time to occupy a full 200 meters of cable so that if there are two stations broadcasting simultanously they will still collide. The problem with the native slot time for a minimum frame of 64 bytes is that .512ms is only good for twenty meters. The whole point is that this extra builtin inefficiency destroys the speed increase so that by my calculations the max 1/2 duplex speed is 371Mbps or 45MB/s.

I don't know if the extra filler bytes are required with full-duplex because no collisions can occur. If not, then that is where one can get the true speed increase of gigabite ethernet.

theoretically, 1000base-T should run fine on cat-5e and should not require specialized twisted pair cabling like cat-6+ or other premimum cables. In practice, better cables are allways a good idea.

Perhaps I am wrong here and if so I would like to be corrected.
 

cas

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P5-133XL said:
The reason why is that the GB standard takes standard ethernet frames that are a max of 1522 bytes long and adds filler (the standard call this a carrier extension) to the end to make them 4096 bytes long.
That's 4096 bits, or 512 bytes.

Note also, that reasonable performance does not require frames greater than 512 bytes in size. While a transmit event must be at least 4096 bit times long, that event may contain multiple frames. In fact, gigabit ethernet supports frame bursts up to 64k bit times long.

Does anybody use half duplex ethernet anymore? At gigabit speeds?
 

P5-133XL

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cas said:
P5-133XL said:
The reason why is that the GB standard takes standard ethernet frames that are a max of 1522 bytes long and adds filler (the standard call this a carrier extension) to the end to make them 4096 bytes long.
That's 4096 bits, or 512 bytes.

Note also, that reasonable performance does not require frames greater than 512 bytes in size. While a transmit event must be at least 4096 bit times long, that event may contain multiple frames. In fact, gigabit ethernet supports frame bursts up to 64k bit times long.

Does anybody use half duplex ethernet anymore? At gigabit speeds?

Cas you are correct, it is 4096 bits or 512 bytes. Thus my analysis doesn't hold water and that inefficiency goes away. There is still inefficiency but many frames are larger than 512 bytes and thus for most purposes, it won't be the big deal I thought it was.

Thanks
 

cas

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P5-133XL said:
There is still inefficiency but many frames are larger than 512 bytes...
Wait, you have missed my point.

Carrier extension applies to transmit events, not frames, under 512 bytes.
 

Mercutio

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I should say, since I saw it a couple days ago, that Dell is selling 8-port managed 1000baseT switch for under $500. Which is really sweet. I'll see if I can dig up a link.
 

Mercutio

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I thought that one had some brains to it.
Oh well. It's the one I was thinking of. It'd be perfect for all the SR/SF members with a half-dozen PCs in their homes. It'd justify your X15, at least. :)

And I was trying to be realistic when I suggested 4x improvement over 100baseT for gigabit. Although I've not seen 8x over copper, either. Best I've managed to do is maybe 70MB/sec. Which certainly isn't anything to sneeze at, but a far cry from 90-something.

And yes, cabling makes all the difference in the world, just like it does for speakers and SCSI setups and telephones.
 

Handruin

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Would you guess with CAT6 cabling that the transfer rates would be higher? What is the best type of copper cable you can purchase these days?

I did a quick search on CAT6 cables and it doesn't look to be that expensive. 1000 feet of this cable is $149.00 at this place:

http://www.a2zcables.com/a2zcables.storefront/3ce292a411bcd3502719424d361d06bc/Product/View/B6B15

This place cost a bit more, but it has a nicer web site. ;)
http://www.cablestogo.com/product.asp?cat_id=715&sku=27192

This may not be the best price, I didn't do much searching, but I don't see why anyone would build a Gb Ethernet without the best cabling. I realize price is a concern for some, but then you shouldn't be buying Gb Ethernet setups if you can’t afford the correct cables.
 

Cliptin

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Solid wire cabling is cheaper but harder to work with. Usually solid wire is used inside the walls.

Stranded wire cables are generally used for patch cables.

That's not to say you can't use solid core for patch cables. I did, but I won't make that mistake again.
 

Mercutio

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Cat6 isn't a standard yet. Like PC2700 three months ago. Buy good-quality Cat5e and be happy your vendor doesn't need to soak you with a name their product isn't entitled to.

On ordinary jobs I buy Cat5e from the local Home Depot. $47.50 a spool. Whatever it is, it isn't quite good enough for GBoC, though.

The first time I did GBoC, the company I was working for specified "premium" Cat5e from MicroWarehouse. I've tried my cheap stuff, and it works OK up to point. The "premium" stuff from MicroWarehouse works better, so the couple of times I've done GBoC since, I've bought their $170 spools of supposedly better stuff.

Probably, there's even better out there, but I don't have a lot of options, locally.
 

Cliptin

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I read somewhere that some manufacturers are "binding" the pairs to keep the twists near exact for the full length of the cable.

It also seems Cat 7 [ISO Class F] is already a standard in Europe.
 

Handruin

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Cliptin said:
I read somewhere that some manufacturers are "binding" the pairs to keep the twists near exact for the full length of the cable.

It also seems Cat 7 [ISO Class F] is already a standard in Europe.

The second link I posted for CAT6 cables says that in the description. The CAT6 cables have bonded wires to keep the twisting throughout the cable.
 
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