vioperf - confusing results

I am also finding vioperf not very reliable because documentation is not clearly explaining what result output to use and results are lower than what IO channel can actually deliver. I am seeing the older vioprobe more reliable. 

Perhaps someone from vertica can explain whether the newer tool has some considerations baked in that I am not seeing. 

Example : 

existing prod host : vioprobe : 

-------- Write ------     ------- Rewrite -----     -------- Read -------

Elapsed  MB/sec  %CPU     Elapsed  MB/sec  %CPU     Elapsed  MB/sec  %CPU

  270.8    974     99        1001.2    263     51        475.5    555     40      

vioperf : 

Write :  MB/s                | 255 

ReWrite:  MB/s            | 460 + 460 

Read : MB/s                | 120

SkipRead :                   | 4900

How can ReWrite ( read + write in parallel) perform better than read or write alone ? There could be a case where same data is read and written and is actually cache serviced in which case results would not be of real-world use, but i am hoping there is something different. 

Vioprobe shows more realistic results . The server in case is a 23 drive RAID10 10K 300 GB SAS, 120MB /sec shown by vioperf is too low and not realistic 

Another example:  ( benchmark server) 

vioprobe: 

-------- Write ------     ------- Rewrite -----     -------- Read -------

Elapsed  MB/sec  %CPU     Elapsed  MB/sec  %CPU     Elapsed  MB/sec  %CPU

  435.0    528     57        957.8    240     29        461.2    498     25 

vioperf: 

Write 460 MB/sec,

ReWrite 245+245,

Read 500 MB/sec

SkipRead 64500 seeks/sec

Here, these results are more aligned  between vioperf and vioprobe. This is a system tuned for IOPS ( SSDs) , hence the high SkipRead. 

It would be useful to specify in the documentation ( and the vioperf initial message) whether Read / Write / Rewrite should match the 40 MB/ core requirement or all three of them.