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-   -   Bargain Hardware Thread (https://www.mersenneforum.org/showthread.php?t=3890)

0PolarBearsHere 2015-11-28 10:17

[QUOTE=LaurV;417438]Yeah, "huston, we have a problem with the black cable, is not connected properly"...[/QUOTE]

Yeah, cabling in Thailand is pretty impressive to look at. At least you can partially narrow it down by looking for the fibre repeater/booster tubes/boxes.

Madpoo 2015-11-28 17:18

[QUOTE=chalsall;417420]Yes, that's what I meant... The problem with zip-ties is they can pinch and/or inadvertently cause a cut or break of the fibre when being installed, moved or removed.

In every submarine fibre landing station I've ever been in (three) all cables were laced AKA sewed. Heck, NASA still uses this technique rather than zip-ties or velcro.[/QUOTE]

I don't zip tie fiber, if that makes you feel any better. LOL

Well, I *do* use them to hold the fiber out of the way but I don't cinch them tight. Just a loose loop to guide the fiber where it needs to be.

I actually migrated away from fiber in my setups. Not too long ago, if you wanted gigabit to your cabinet/cage at a colocation, fiber was pretty much your only option, but then Gig over copper came out and became common with Cat6/Cat5E and it's just so much easier. No GBICs/SFPs to worry about, etc.

We'll probably see that with 10Gbe before too long, becoming more common at the provider level (cat6a/cat7 copper). I'm nowhere near the point where I need 10Gb into our cabinet though... our bandwidth isn't quite that high... yet. :smile:

Inside our network, our servers have 4 Gb ports each that I channel into the stack which, again, is enough for now. A lot of HP's new servers do have a common option for 10Gb ports though

chalsall 2015-11-28 20:45

[QUOTE=Madpoo;417518]I don't zip tie fiber, if that makes you feel any better. LOL[/QUOTE]

:smile:

[QUOTE=Madpoo;417518]I actually migrated away from fiber in my setups. Not too long ago, if you wanted gigabit to your cabinet/cage at a colocation, fiber was pretty much your only option, but then Gig over copper came out and became common with Cat6/Cat5E and it's just so much easier. No GBICs/SFPs to worry about, etc.[/QUOTE]

Copper now works fine for very high speed at short distances. For a while I worked in longer distances. Sometimes kilometres; sometimes hundreds of kilometres.

I have to say, it's pretty cool when a large ship, and many divers, have to be used to bring to the shore the multi-fibre submarine-cable capable of TB/s....

bgbeuning 2015-11-29 03:12

[QUOTE=VBCurtis;417336] "Those are great servers, I've used them at like 4 different employers. Hey, I have an older one in my garage. Want it?"
[/QUOTE]

Score! I would like to hear your experiences with it. I do not see Keyboard, Video, Mouse (KVM)
connections, just Ethernet connections.

My current favorite machine is an "HP 8300 Elite" with i5-3570.
It only draw 60 Watts under full load and can do an M39,000,000 double
check in 2 weeks. A Xeon 5355 take 7 weeks.

If anyone goes looking for the 8300, be warned I have seen five different CPU in it.
i5-290, i5-790, i5-2400, i5-3470, and i5-3570. Some sellers (like Walmart) just
say i5 without saying which one.

VBCurtis 2015-11-29 17:57

[QUOTE=bgbeuning;417562]Score! I would like to hear your experiences with it. I do not see Keyboard, Video, Mouse (KVM)
connections, just Ethernet connections.

My current favorite machine is an "HP 8300 Elite" with i5-3570.
It only draw 60 Watts under full load and can do an M39,000,000 double
check in 2 weeks. A Xeon 5355 take 7 weeks.

[/QUOTE]
An i5-3570 can draw 77W under full load on its own, according to Intel specs. Your 60-watt spec is not possible for a computer using that chip unless it's at idle.

bgbeuning 2015-11-29 20:01

[QUOTE=VBCurtis;417643] Your 60-watt spec is not possible for a computer using that chip unless it's at idle.[/QUOTE]

The uptime (1) command says 4.0 and my current meter shows 0.54 Amps.
Where did I go wrong?

Mark Rose 2015-11-29 23:03

If you cat /process/cpuinfo , what does it say for CPU frequency?

bgbeuning 2015-11-30 01:25

[QUOTE=Mark Rose;417692]If you cat /process/cpuinfo , what does it say for CPU frequency?[/QUOTE]

Model Name Intel Core i5-3570 CPU 3.40 GHz
cpu MHz 3599.882
bogo mips 6784

The current meter does not work when put around a power cord.
So I made a 1 ft long cord with the 3 wires broken out so I could
measure a single wire. The current meter is one of those loops
you put around a wire.

For a Dell 1950 dual Xeon, I got a current reading of 3.0 Amps (360 watts).

VBCurtis 2015-11-30 02:24

I suspect your current meter's accuracy much more than I suspect Intel's documentation.
120w is possible for a desktop, but 60 just doesn't make sense. Perhaps you're measuring half the current.

bgbeuning 2015-11-30 11:24

[QUOTE=VBCurtis;417716]I suspect your current meter's accuracy much more than I suspect Intel's documentation.
120w is possible for a desktop, but 60 just doesn't make sense. Perhaps you're measuring half the current.[/QUOTE]

I measured the current draw of a 40W light bulb and got the expected result.

Xyzzy 2015-11-30 14:27

[QUOTE=bgbeuning;417751]I measured the current draw of a 40W light bulb and got the expected result.[/QUOTE]Can you compare a light bulb load to a computer load? (We don't know!)

Is this link useful?

[URL]http://www.allaboutcircuits.com/textbook/alternating-current/chpt-11/power-resistive-reactive-ac-circuits/[/URL]


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