You need live with that, if you use GMS or GroupWise Web you are pushed to use SOAP over "SSL".

given that encryption is a CPU intensive operation, how busy are servers on either end?  perhaps one or both is CPU constrained with SSL turned on, and just adding cores speeds things up.   check RAM as well, though not as critical as CPU for this.

The speed degradation is certainly not reasonable or a match to any other SSLized operations I've seen before, hence I suspect a resource constraint.

We do not use GMS (although I think that one can be changed to non SSL) and we still use old WebAccess (SOAP SSL can be switched off or on). In future we will use GWWEB and it is a reason, why I'd like to get rid of problem before we go live with Retain.

With this performance my initial archive job would need 60-100 days for 10 Mio messages.

Exactly this is a reason why I asked community for experience in comparison of performance.  Of course SSL need more resources, but 40-50 times slower is too much.

I think I have more then enough resources. Both server are less then 10-20% on CPU and have enough free memory.

I have same speed as you, between 1 - 2 m/s, I had here thread about speed and I was the slowest one. Plenty RAM, unlimited CPU, very quick SAN and this kind of performance. 

The problem has been resolved by support.

changing default HTTP,SOAP to SOAP,HTTP makes my retain system be 10-15 times faster with SSL.

vi /opt/beginfinite/retain/RetainWorker/WEB-INF/classes/config/attachment.properties
# This properties file belongs to the Worker.
# --------------------------------------------------------
#attachment.handler.list= HTTP,SOAP
attachment.handler.list= SOAP,HTTP

Vlado  Thanks for sharing with other community members!

I had a customer make this change yesterday and they went from 1.2 m/s to 6.33 m/s with SSL enabled.  I wish it had the very high m/s performance when SSL is disabled on SOAP.

Ed, maybe a crazy idea but I tried it.

I have created a second POA in my test environment. This new POA has been configured with insecure SOAP.

Afterwards I had to re-configure my Retain GroupWise Module.

And my Worker1.

Now I use secure SOAP for GMS and web client but insecure SOAP for Retain ... 

I am excited to see what your new m/s throughput will be.  My guess is 40 m/s.