how many ssds could i fit in this psu?

Take it apart and put as many SSD's as you can afford to buy, cellotape them together for maximum space utilisation. Or, spend even more money on NVMe SSD's and you could fit at least 20 inside. Don't forget to come back and post some screenshots and benchmark results for other equally challenged extreme PC modding enthusiasts.

does this have the 80 plus seal?

This power supply has the 80 plus gold seal. And also it looks amazing and the power cables are fantastic and beautifully packaged there is also a little bag of cable ties and some cool magnets was very happy with this purchase myself. Hope this helps

will this fit rog strix b450-f board

Yes, it will connect to and run that mother board and whole build should run fine. Personally I'd bag the 850w as pound for pound it works out cheaper per watt and will provide some additional headroom for a hungry graphics card and other peripherals you might want to add later.

Brand	ASUS
Product Dimensions	15 x 16 x 8.6 cm; 1.8 kg
Batteries	1 Lithium Ion batteries required.
Item model number	90YE00A4-B0NA00
Manufacturer	ASUS
Series	ROG Strix 850G White Edition
Colour	White
Form Factor	ATX
Computer Memory Type	DIMM
Hard Disk Description	Solid State Drive
Voltage	220 Volts
Wattage	850 watts
Operating System	Windows
Are Batteries Included	No
Lithium Battery Energy Content	2 Kilowatt Hours
Lithium Battery Packaging	Batteries packed with equipment
Lithium Battery Weight	2 Grams
Number Of Lithium Ion Cells	5
Number of Lithium Metal Cells	5
Item Weight	1.8 kg
Guaranteed software updates until	unknown

ASUS ROG Strix 850W White Edition PSU, Power Supply (ROG heatsinks, Axial-tech fan design, dual ball fan bearings, 0dB technology, 80 PLUS Gold Certification, fully modular cables, 10-year warranty)

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