PowerMac versus XServe

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There have been some topics posted here about people converting their old, under utilized Macs to servers. This might seem like a bizarre question, but I was wondering if things could go the other way and would an Apple Xserve machine be a terrible, decent, or fantastic desktop computer? I was looking at the AppleStore spec.s just now. They have a ton of processing power, most of the standard hardware ports of a Mac, even a cheesy video card for making podcasts, and decent expandability. What am I missing? I know that they are heavy and pricey (compared to a PowerMac though?).

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Xserves are basically Mac Pro

Xserves are basically Mac Pros condensed into a 1U rack chassis. They offer the same level of processing power, yet are actually less expandable than a Mac Pro (fewer drive bays, expansion slots, onboard ports, etc.). In a pinch they'd work as a desktop machine, but I don't think you'd be able to stand the loud fans for very long.

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Reliability Differences?

In regards to computer hardware, I will sometimes see the phrases "not meant for mission critical applications", or "enterprise class." Is there hardware/software reliability difference between a MacPro and an Xserve machine? I saw that the Xserves have dual redundant power supplies.

@ Dr. Webster, should I assume that the fans are for keeping the extra processors and the extra power supply extra cool?

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Re: Reliability Differences?

mutant_pie wrote:

Dr. Webster, should I assume that the fans are for keeping the extra processors and the extra power supply extra cool?

Servers tend to be hefty in the fan department. I was going to set up a dual xeon Compaq server salvaged from work to run my home server setup, but the fans on it were so loud you could hear them on the main floor (server is in the basement).

The redundant PSUs are usually on a low-power standby unless needed, so the hefty fans are there as a safety feature. For servers that have a number of high-spinning hard drives, more cooling was necessary.

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Re: Reliability Differences?

eeun wrote:
mutant_pie wrote:

Dr. Webster, should I assume that the fans are for keeping the extra processors and the extra power supply extra cool?

Servers tend to be hefty in the fan department. I was going to set up a dual xeon Compaq server salvaged from work to run my home server setup, but the fans on it were so loud you could hear them on the main floor (server is in the basement).

The redundant PSUs are usually on a low-power standby unless needed, so the hefty fans are there as a safety feature. For servers that have a number of high-spinning hard drives, more cooling was necessary.

Since servers are typically more compact airflow-wise than desktops, they need many fans to ensure adequate cooling. Take a look at the Mac Pro; that bad boy has a number of big fans and plenty of open space inside for air to flow. The XServe will put out just as much heat from its Xeons, but its 1U chassis means there's less room for airflow. Thus, you need many fans, all spinning at high speed, to make up for it. (The fact that those fans are noisy is simply a matter of economics; since XServes are meant to be installed in racks in data centers, it doesn't matter if their fans are noisy -- noisy fans are cheaper to manufacture.)

Server fans can also come in hot-swap and redundant varieties; hot-swap fans, as you might imagine, allow you to replace them without shutting the server down, while redundant fans have identical spares sitting on standby, ready to spin up should the primary fans fail.

When it comes to redundant PSUs, there's nothing special that needs to be done on the motherboard. All of the magic is done by the power distribution board. Unfortunately there's no industry standard for how redundant power supplies will operate. Some will work in a "half-load" mode, with one ready to ramp up to provide all of the power to the system should the other fail. Others will shoulder the load on one PSU, while the other stays in standby. Then there are the weird 2+1 setups, where you can have 3 power supplies installed but the system requires 2 just to keep running. Some systems even offer scalable power; our blade system at work has 4 power supplies installed, all of them 220V, with the minimum number of PSUs required being based on how many blades and expansion modules are installed in the chassis. (Cisco chassis usually work the same way.)

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Reliability & Stability

Aside from the reliability of the PSU's and the fans, I'm curious about the actual reliability of the running machine/software on an Xserve machine versus a MacPro. Do these machines crash? Are they considered to be "enterprise class" and capable of "mission critical" perfomance?

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Computers crash, regardless o

Computers crash, regardless of whether they're a desktop, laptop or server. Crashing is a software problem, largely unrelated to hardware. The Mac Pro is actually based off of Intel's server chipset line, so to specifically answer your question, a Mac Pro and XServe should be about as reliable from a hardware standpoint.

I would say Apple has never shipped an "enterprise-class" or "mission-critical" machine. While those terms are nebulous at best, generally machines of that caliber have significantly more redundancy than what an XServe offers (the ability to RAID or hotspare RAM, redundant drive controllers, hotswap/redundant expansion cards, etc.).

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G5 2.3Ghz DP xserve as desktop

Yeah
I brought in a G5 xserve to my workplace so we would have a mac to use.
It was super cheap on ebay but I had to install a PCI video card
and wrangle with the whole OS install thing. Some Xserves don't like
Target Disc Mode so I had to remove the hard drive and put it in my other
mac and then install and so on and so forth.
Long story short- The thing kicks ass but is very LOUD.
I mean like "turn up the TV so you can hear it" LOUD.
But at work (modern sign shop) we have huge inkjets running full time so it is not an issue.
Also the cases are really big but really flat so you have all kinds of creative mounting options.