What is the maximum throughput of AFIO's closure execution engine aka how many IOPS can I push with AFIO?

For v1.3 of the engine, maximum ops dispatch throughput is approximately as follows, where the values for call() might be for use as a closure engine whereas the values for completion() might be for max filing system IOPS^[12]:

Table 1.16. Maximum null closure dispatch rate on a 3.5Ghz Intel Core i7 3770K for AFIO v1.3^[a]

Operating system	`call()` unchained	`call()` chained	`completion()` unchained	`completion()` chained	Raw ASIO
Microsoft Windows 8 x64 with Visual Studio 2013	1148070	704051	1850090	877899	2750088
Relative to ASIO	42%	26%	67%	32%	100%
Relative to AFIO v1.21	+1%	+16%	+14%	+36%
Relative to AFIO v1.1	+26%	+18%	+19%	+20%

Ubuntu 14.04 LTS Linux x64 with GCC 4.9.2	1149470	1100650	1629110	1308240	1927300
Relative to ASIO	60%	57%	85%	68%	100%
Relative to AFIO v1.21	-11%	+8%	+10%	+9%
Relative to AFIO v1.1	+5%	+39%	+14%	+20%

We hope that ~600k min IOPS surely ought to be enough to max out any SATA III SSD — it should even max out any mid range PCIe based SSD too, and if paired with a CPU with more cores, AFIO's almost wait free design ought to scale out fairly well too such that it may be able to max out even top end PCIe SSDs, some of which can push 10m IOPS now.

^[12] The phrase “might be” is important: a null closure benchmark will always have dispatch rate problems i.e. the closures being executed take less time to execute than the time to dispatch them, so these figures are best read as maximum dispatch rate, not maximum IOPS.