Upgrading to Mavericks Fails, Still

Question

I wrote this update, largely to kill time.  Earlier today, I rode a NuStep stationary bicycle, 50-minutes.  At a Workload of 9/10, I pedaled 4,850-steps in 50-minutes, which makes an average of 97 steps/minute.
[With many minutes I spend warming-up, this means that I spend a few minutes _above_ 100 steps/minute. Whew!  A benefit from riding this hard is that I feel Great, awhile.  :-) ]
I feel that upgrading to Mavericks will _require_ that I buy a new iMac.  (My current iMac has 4 GB of RAM it runs Mac OS X v10.8.5 & it was made in mid-2011, according to About this Mac under the Apple menu.)
Endlessly when I just try to _get_ Mavericks with Software Update, instead of getting Mavericks I see this:  "Your request is temporarily unable to be processed.  Please try again later."  [ & later & later & … & later & Later:  Try, Never!  :-( ]
As measured by SpeedofMe (an HTML 5 Internet Speed Test) on 17 Apr 14, my speed at downloading is 6.21 Mb/sec.  With Mavericks 5 GB large, its download _would_ take some 5,000 MB / 6.21 Mb/sec ...  BUT  HOLD - ON, please:
I wonder, are B & b the same?  Or, does b mean bits & B mean Bytes?  So maybe a factor of 8 belongs?  (Are there 8 bits in 1 byte?)
[Mega is thousand & Giga is million, so Giga/Mega = 1,000, correct please?  Sorry, I live years-removed from  _that_  particular knowledge.]
So, I feel that upgrading to Mavericks will _require_ that I buy a new iMac.  In this way, my Mac will have Mavericks installed, already.  This would eliminate all of this _fuss_ about downloading Mavericks.
But Mac OS X v10.8.5 runs well.  So do you believe that I should buy a new iMac with Mavericks installed, already?  I thank you.  :-)

Answer 1

Dear Timothy Fink of Minnesota,
Thank you at confirmng my idea that MB/Mb = 8.
Please rest-assured that I'm in No Hurry to get Mavericks.  But I copied your response into my Journal i.e., my daily record of events in my life.  [So Timothy, you are as well-as Enshrined.  Thank you.]
P. S.  I need to ask, "Where _are_ you in Minnesota, please?"  From mid-1985 through 1990, I lived in Minneapolis.  In the-end I earned a PhD in Chemical Engineering.  I earned a PhD after I worked-with arguably the two, toughest advisors there:  Professor H. T. Davis & Professor L. E. Scriven.  (Both _brilliant_ men are deceased today.  Neither has a child, though.)