Intel Atom and Gigabit

[JAG87]

Does anybody have experience with Intel Atom and Gigabit network speeds?

I just built my home server based around the Atom, and I can't seem to get more than 25 MB/s transfers speeds. My network is capable of more than that, as I have tested between my laptop and my desktop. I see the cpu usage at 40-50%, is the Atom a bottleneck to Gigabit speeds because of CRC checks? I wish my switch supported jumbo frames

Anybody with experience, please chime in.

 

[JackMDS]

The ATOM board per-se has nothing to do with Giga speed. If the NIC is Giga and Network is optimized for Giga you should get 50MB/sec. or more.

First culprit is usually the Giga switch, some of the Entry Level Switches (including the ones that are on a Wireless Routers) are "Lame Ducks".

The best inexpensive Giga switch is this, http://www.newegg.com/Product/Produc...82E16833156250

Optimize the Computer's TCP/IP using the setting for your Internet connection type and double the recommended TCP RCwin. (download here, http://www.speedguide.net/downloads.php ).

In most cases that will improve the Giga LAN transfer.

Using the above switch with onboard Marvel NIC to Realtek NIC I get this.

RCwin Not optimized with Netgear mediocre Giga switch.

Every thing same but RCwin doubled on the computer the switch linked above.

 

[JAG87]

Hi Jack, thanks for the reply.

First, I have a linksys SD2008 ver3 (pity no jumbo frames), which I know is not the culprit since I can transfer at almost 60 mb/s from my laptop to my desktop (which is close to the maximum reading speed of the hdd in the laptop).

So I know it's not the switch.

Second, all three machines use the exact same software configuration. The differences are desktop is Realtek (backed by beefy hardware), laptop is Intel (backed by decent hardware), and server is Realtek (backed by the mediocre atom). All things the same, I am trying to figure out if the Atom platform is having a hard time keeping up with the gigabit tcp transfer.

On that last note, your RWIN tweak might prove handy. I will try it out.

If anybody else has any thoughts, please post. Google isn't being very helpful with this topic.

 

[Jeff7181]

It should be fairly easy to determine if the Atom CPU is a bottleneck. Monitor CPU usage during a large transfer.

 

[Binky]

I have an Atom-based WHS machine (Acer H430) that does pretty well. I've seen as high as 70mb/sec sustained, and I currently get about 55mb/sec sustained. This is with Seagate 5900rpm green drives I've seen 25mb/sec on the same machine at various points in my home, and I always found it to be a cabling issue.

 

[JAG87]

I have an Atom-based WHS machine (Acer H430) that does pretty well. I've seen as high as 70mb/sec sustained, and I currently get about 55mb/sec sustained. This is with Seagate 5900rpm green drives I've seen 25mb/sec on the same machine at various points in my home, and I always found it to be a cabling issue.

I went to check and guess what .. that room has cat 5 cabling instead of cat5e..

*double face palm*

Thanks for the idea Binky.

 

[ViviTheMage]

my DIR-655 does not support JUMBO frames, but I get nice 75-95MB/S transfer speeds...didn't have to tweak anything either.

Going to/from Windows 7 64bit, Windows XP 64bit, Centos 64bit

 

[ScottMac]

I went to check and guess what .. that room has cat 5 cabling instead of cat5e..

*double face palm*

Thanks for the idea Binky.

GigE works fine over (and was originally spec'd for) properly terminated and maintained Cat5.

Off the top of my head, I'd blame the ATOM ... it's a pretty lame little CPU ...I have a netbook with an Atom (tried it with XP, &Starter, and W7HomePro ... no serious difference), and it works its ass off doing common application stuff. I can't imagine it being competent for massive throughput (like GigE) and doing anything else in the meantime.

It's OK for surfing (and mp3s, audio books, videos ...) but any real data crunching/throughput of any sort ... I don't think so. Certainly, I could be wrong, but my impression is that the Atom is operating like a old crippled Celeron with a memory shortage.

 

[Emulex]

what about tcpackfrequency? nagle?

 

[SammyJr]

I have one of those SuperMicro Atom based server motherboards. I can hit 100mb/second easily on my RAID array over the network.

 

[JAG87]

SammyJr

I also have the Supermicro Atom 330 board, and I am getting 25 mb/s. So it must be my network, or my cabling rather, because in other rooms I have cat5e and I get much better speeds, usually limited by hdd.

ScottMac, gigabit might be fine over short cat5, but you gotta realize I am running insanely long distances (every room in the house down to the furnace in the basement). I am thinking gigabit over 50m of 10+ yr old cat5 isn't producing the best results.

 

[d33pt]

why don't you move it closer with a shorter cat5e patch cable and see if it makes a difference? easy enough to do that.