Cryptic background
One of the powerful features of the T-series servers is its hardware crypto acceleration,
which dramatically speeds up the compute intensive algorithms needed to encrypt and decrypt data.
Previously, administrators setting up logical domains on older T-series servers had to explicitly
assign crypto resources (called "MAU" for historical reasons from the T1 chip that had "modular arithmetic units") to domains that had a significant crypto workload (say, an SSL based web server). This could be an administrative burden, as you had to choose which domains got the crypto units, and issue the appropriate ldm set-mau N mydomain commands.
The T4 changes things
The T4 is fast. Really fast. Its clock rate and out-of-order (OOO) execution that provides
the single-thread performance that T-series machines previously did not have.
If you have any preconceptions about T-series performance, or SPARC in general,
based on the older servers
(which, it must be said, were absolutely outstanding for multi-threaded applications),
those assumptions are now obsolete. The T4 provides outstanding.
performance for all kinds of workload, as illustrated at
https://blogs.oracle.com/bestperf.
While we all focused on this (did I mention the T4 is fast?), another feature of the T4 went largely unnoticed:
The T4 servers have crypto acceleration "just built in" so administrators no longer have to assign crypto accelerator units to domains - it "just happens".
This is way way better since you have crypto everywhere by default without having to manage it like a discrete and limited resource. It's a feature of the processor, like doing an integer add.
With T4, there is no management necessary, you just
have HW crypto everywhere all the time seamlessly.
This change hasn't been widely advertised, and some administrators have wondered why there were unable to assign a MAU to a domain as they did with T2 and T3 machines. The answer is that there is no longer any separate MAU, so you don't have to take any action at all - just leave the default of 0.
Summary
Besides being much faster than its predecessors, the T4 also integrates hardware crypto acceleration
so its seamlessly available to applications, whether domains are being used or not.
Administrators no longer have to control how they are allocated - it "just happens"