How does Xeon E 5645 2.4 GHz compare to i-7 2600K 3.4 GHz ?

I bought Dell workstation T-7500 with Xeon E 5645 2.4 GHz with other configuration like RAM, HDD, Win-7, etc same as Dell XPS 8300 desktop with i-7 2600K 3.4 GHz

Both have WD 500 GB 7200 RPM ( No SSD )

But I am finding that workstation seems slower than desktop.

So is it the processor that is slow or something else ?

Percentage wise How much slower it should be ?

They want extra $ 500.00 to upgrade to Xeon X5650. 2.66 GHz. Would that be as good as i-7 2600K 3.4 GHz or better?

OR

Getting dual processor with two Xeon E5645 2.4 GHz better ? Both costs extra $ 500.00

 

I'm not sure what your definition of "slower" is but despite being a full 1ghz slower in clock speed, the workstation should nearly equal the desktop with the exception of graphics. That would be because it has 6 cores instead of 4 and 12 threads instead of 8. What graphics controllers are in them? Are they add on controllers or onboard?

Here are the Intel Specs on the two processors.

i7 2600K - Xeon E5645

 

it is not the best benchmark but a remote idea
dual xeon
http://www.cpubenchmark.net/cpu.php?cpu=[Dual+CPU]+Intel+Xeon+E5645+%40+2.40GHz
single xeon
http://www.cpubenchmark.net/cpu_lookup.php?cpu=Intel+Xeon+E5645+@+2.40GHz
upgrade xeon
http://www.cpubenchmark.net/cpu_lookup.php?cpu=Intel+Xeon+E5649+@+2.53GHz
i7-2600
http://www.cpubenchmark.net/cpu_lookup.php?cpu=Intel+Core+i7-2600+@+3.40GHz

well so if it worths the dual xeon or the i7?
do you use software that can use that many cores??
if not go for the i7

slower than desktop which desktop you have?? that makes your xeon feel slow?? also the graphic card or hard drive have a huge impact how the system feel