Intel® Xeon® 5600 series processors up to six-cores, 6.4GT/s (Intel QuickPath Interconnect) and 12MB shared cache. Turbo Mode and HyperThreading technology on select processors. All processors are 64-bit, support Intel DBS (demand-based switching) andIntel VT (Intel Virtualization Technology). Note: Intel TXT is not supported.

Source:  Precision T5500 Spec Sheet.pdf

CPU's can be compared side by side at game-debate.com.  Computer builds can be checked and compared at userbenchmark.com.

So, if you don't think you're CPU is good enough, you can compare it with a CPU you're looking at to see if it's that much better.

The above might not be a final answer, but I think it's a good place to start.

The spec sheet also has a list of compatible GPU's.  But if you're looking at one not on the list (as your Precision goes a ways back), there's userbenchmark.

Hi bradthetechnut,

Thanks for your answer

I've already seen this docs. the most powerful CPU in 56xx series is X5680. However, its power consumtion is 130W (in my E5620 is 80W). I am not shure my MB is able to work with this CPU.

GPU is not a problem, I believe GTX 1060 will be ok :)

Hi @Caezar93 ,

Correction: The fastest processors in Westmere-EP family should be X5687(3.6 GHz) for quad core and X5690(3.47 GHz) for six core. Check this out: List of Intel Xeon microprocessors - Wikipedia

And here's what you need - UserBenchmark: Dell Precision WorkStation T5500 Compatible Components

You can see builds installed with those 130w CPUs. They should be fine with your T5500.

Hi @Caezar93 ,

I tried my best and found this thread as reference.

A Dell Technical Support listed MB for T5500 with 3 different part numbers, 2 of them support Westmere Intel E56XX/X56XX and the rest older one support Nehalem Intel E55XX/X55XX. The most important sentence: 

In theory (not tested): Westmere should work on the older motherboard as well if you are running latest BIOS.

Then the last reply of this thread confirmed X5660 CPU, member of X56XX, do works on the older motherboard. Although those part numbers not exactly the same as yours, theory should be the same. Moreover, checked on page 28 of the official T5500 Technical Guide and X5580 listed as supported CPU which require 130w as well, without stating any specific requirement on motherboard version. In conclusion, Intel E56XX/X56XX should be work on your existing T5500 motherboard, including those require higher wattage like X5680.

For the example of T5400 you quoted, it's totally a different kind of story. Both E5430 and E5450 listed with the same value of L2-Cache/FSB/Voltage/TDP(Wattage)/Socket, only differences on speed(frequency) and multiplier. They should be work on the same motherboard. CPU compatibility may not be the reason why E5450 not working on one of your T5400. 

How can I tell if my T5500 is upgradeable? I read not all are..

Want to get new CPUs, video cards, and ssd

@Mindchamber it all depends on the current spec of the system that you have as that will determine which motherboard, graphics card and storage options you have.

The best way to check what motherboard you have is by going to the the support site www.dell.com/support and entering your service tag. You can then check the configuration of the system and it should give you a part number.

You want to cross reference the part number with the information provided by Justin in this post - https://www.dell.com/community/Desktops-General-Read-Only/Dell-Precision-T5500-CPU-Upgrade/m-p/4475537/highlight/true#M967518

Once you have that info you then check the specification documentation here to see what processors work with your motherboard and then see what graphics cards are an upgrade to your current model - http://i.dell.com/sites/content/business/solutions/engineering-docs/en/Documents/Precision-T7500-T5500-Technical-Guide.pdf?prg=1&VEN1=12578053-9101479-v0304000114163f6303680fd24a418696ae9dcc6145f0&AID=9101479&cjevent=b1745977052e11ea817400320a1c0e11&dgc=CJ&DGSeg=DHS&cid=198375&lid=45846&acd=12309198375458460&VEN3=110405013081978313

What I will add though is that the system is now 10 years old and isn't certified for use with Windows 10. If you plan on installing Windows 7 on it, support officially ends for that operating system in January 2020. Were you considering running Linux on it?

Alan

What can I do if I have an E5506? Can I put a Xeon X5650?

My motherboard is 0D883F

Yes, the X56XX 6 core/12 thread processors will work in your system. I think the fastest Xeon you can go is the X5690 which runs at 3.4GHz which is what I have in my system but something you need to know when putting these higher wattage processors in your system is the heat they will generate. My motherboard mounted CPU was reaching temps of almost 90 deg Cent. and started throttling due to heat. Had to add and after-market cooler and additional fans to cool it down. Just an FYI - I just sold two matching X5650's on E-Bay for $20. You can find them pretty cheap. If you can spend a little more get the X5675 or better.  

Hi, I have a doubt, hope someone can help me, I have x5675 processor in my t5500 and Iwant to buy the riser board for the 2nd cpu, but I dont know What processor should I buy, is it OK to install an x56xx series Or an e55xx? Or What limitation do I have? Thanks in advance