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I know the Xeon processors have been around for a long time and are mostly used in servers, but I am curious, why do people not use the Xeons in a high performance desktop?

As far as I know about the best desktop processor out there now is the Intel Core i7 line. The i7's and Xeons are both quad-core processors, what is the main difference in these? I just saw that the MacBook Pro's are using the quad core Xeons instead of the i7's.

6 Answers 6

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The current line of Xeons are based on the same architecture as the i7. The difference is usually that the Xeons are the cream of the crop. They run cooler and at lower voltages and are spec'd for 24/7 continuous usage. Otherwise, performance is usually identical. Xeons are able to be used in multi-socket motherboards, where i7s are not (which is why the Mac Pros use them).

Xeons are also usually the first to be updated. There are 6-core Xeons, but not i7s yet, though they are still based on the same architecture.

The additional reliability of the Xeons is very important in servers, especially rackmount and blade-enclosed servers where the lower heat dissipation and power consumption are essential. These benefits usually don't mean too much to all but the most extreme overclockers though, so people in the desktop segment usually ignore it due to the enormous difference in the price of both the CPU and the motherboards needed to support them.

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    @jasondavis - Yes, but that is money that is better spent on better/more video cards, RAM, SSDs, etc. In almost all cases, unless you're really spending an ass-load of money, you can spend those $$ elsewhere for better performance.
    – MDMarra
    Mar 22, 2010 at 21:39
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    The pipelines are the same, however the Xeons also tend to have more cache and more registers. This along with dual socket capablity is why they are used in high end workstations. More registers is very important with large numeric datasets.
    – spowers
    Mar 22, 2010 at 22:37
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    Is there any DATA to support XEON being more reliable, or is XEON just a brand name, and i7 another brand name, for members of an identical CPU family from Intel, offered at different price points? For example, is the multi-core feature just a matter of unlocking a chipset feature, or is there actual silicon gates involved in enabling multi-core? Are the multi-core and ECC DRAM features on the die of the i7 and just not connected to the relevant pins in the LGA 2011 socket?
    – Warren P
    Sep 15, 2013 at 20:52
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    They're different chips made with similar technologies. Things like NUMA support and multi-socket support do not exist in the i7 line. I'm not sure what data you're after. Perhaps you're looking for something like the E7 family whitepaper from Intel? If you're doubting that Xeons are superior CPUs, you should ask yourself why an enormous amount of the server market share runs on them. If there weren't real benefits, wouldn't someone have figured that out by now?
    – MDMarra
    Sep 15, 2013 at 23:16
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    @MDMarra "If there weren't real benefits, wouldn't someone have figured that out by now?" -- You overestimate us.
    – Jason C
    Jun 21, 2014 at 22:48
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Another difference between Xeon and i7 is that the Xeon supports ECC memory, the i7 does not.

Also, some Xeons are designed to work in multi-CPU systems, whereas absolutely no i7 models do. As such, if you want a multi-CPU system, you must use nothing less than a Xeon.

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why do people not use the Xeons in a high performance desktop?

They do, but they're referred to as "Workstations".

Workstations are essentially a server, but with expansion abilities more like a desktop.

You get all the benefits of a server (symmetric multiprocessing, stability, management, hot-swap, etc.) plus the things you wouldn't normally have in a server, like video card(s).

Check out Intel's Workstation pages to find out about their current Workstation boards like the S5000XVN, S5520SC, and WX58BP.

We've been building systems like these (SMP Xeon workstations) for years for AutoCAD usage at many clients, and for various number crunching machines at the local university (engineering, stats, astronomy, etc.).

They're awesome to use, and expensive. :)

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    You're arguing semantics about desktop vs. workstation. They are interchangeable, having a Xeon does not make it a workstation.
    – MDMarra
    Mar 23, 2010 at 14:39
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    I'm not arguing anything, I'm going by Intel's own designations. Workstation platforms have the features and benefits of a server, plus the benefits of a desktop. If we use your line of thinking then the differences between a "desktop with a shared folder" and a "file server" are also just 'semantics'. :) Mar 23, 2010 at 20:57
  • You brought up a "desktop with a shared folder" and a "file server"
    – MDMarra
    Mar 24, 2010 at 1:41
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    You brought up semantics. I was speaking about designated hardware platforms that differentiate between Intel computers the take their desktop oriented CPUs and their ones that use Xeons. Since the (first) question was "why don't people use Xeons in high-end desktops". The answer is they do, but they're referred to as "Workstations". It's OK if you don't quite grasp the difference, as you probably haven't built too many $10,000+ Xeons workstations. I'm someone who has, so I know there's a very distinct difference. I didn't downvote you or anything, so I'm not sure why you're all attacky? Mar 24, 2010 at 2:48
  • Workstation means Intel charges you more. :-)
    – Warren P
    Sep 15, 2013 at 20:54
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http://ark.intel.com/ This is the intel product comparison site. You can look through and compare the different intel processor lines and see many of the design and feature differences.

In addition to what has been mentioned: Some of the Xeon's also support a couple advanced processor features that the desktop iX processors do not. Most of these however are only relevant and useful in scientific and advanced computing needed in workstations, massive multi-processor machines, and CPU intensive applications.

Advanced power management and thermal properties are essential to high performance computing and servers. In this market, electricity and cooling are significant costs. Using a certain processor that is designed for the server environment might save a company lots of $$$ each month in power bills if it can process much more efficiently. This is just one example.

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Also not previously mentioned in the other answers,

Much larger caches on Xeon where the number of cores are roughly equal. Although the L3 shared cache on the top of the line 10 core xeon is a whopping 30MB.

Higher core count on Xeon. Currently 6 cores on i7 vs 10 cores on Xeon.

And some extra processor instructions on Xeon's such as Intel Trusted Execution Tech and hardware AES etc. You generally wouldn't see these features used on a desktop machine so you can see Xeon's are geared towards servers or machines with special requirements.

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    Actually, TXT exists on "enterprise" oriented desktops and laptops that don't contain Intel Xeon processors.
    – user314104
    Jul 30, 2013 at 1:28
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The core i series parts and the xeon parts start from the same basic designs but intel cripples them differently.

Desktop parts (core i series) don't support ECC ram and don't support multi-socket. They may or may not support overclocking.

Workstation/server parts (xeon) support ECC ram, often registered ECC which allows support for much large modules. They usually don't support overclocking. They usually cost more for a given clockspeed. They usually have more cache than desktop parts. They may or may not support multi-socket.

In general the xeons aren't much if at all better than the desktop parts in desktop workloads. Desktop workloads don't benefit that much from more cores, more cache, or crazy ammounts of ram they do best with a relatively small number of high-clocked cores.

As to why apple are putting xeons in their laptops I don't know. Maybe they are hoping that people with more money than sense will think xeons are cool. Maybe they think there are some pro workloads that will benefit from the extra cache.

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