SFX versus ATX power supplies: compare SF750 and RM750x dimensions
Two Corsair 750 W units differ in physical format, dimensions and cable family. Compare exact SKUs with the configured case, not the output label alone.
Updated:
Equal output labels do not mean equal physical fit
Corsair SF750 CP-9020284-UK is an SFX unit; the cited RM750x CP-9020199-UK is an ATX unit. Both list 750 W continuous output, but they differ in dimensions, cable family and documented platform details. Choose the physical format explicitly supported by your case before treating wattage or efficiency branding as the deciding feature.
The full SKU matters because SF750 and RM750x have existed in different generations. This comparison does not transfer a current SF750 Type 5 statement to an older SF750 or apply a different RMx generation dimension. The actual older HX620W photograph is another historical Corsair product: familiar branding and supplied leads do not identify either compared SKU or its cable family.
Compare the current source-listed dimensions and cable families
Corsair’s SF-series guide identifies the SF750 model RPS0205 with length 100 mm, width 125 mm and height 63.5 mm. Its UK product page identifies CP-9020284-UK, SFX format, Type 5 cables and ATX 3.1 compliance. The ATX version is a standard-compliance description, not a claim that the unit has a full-size ATX physical enclosure.
The cited RM750x page lists 150 × 86 × 160 mm dimensions, ATX physical format, Type 4 cables and ATX12V version 2.4. Matching 750 W output does not make Type 4 and Type 5 modular leads interchangeable. Confirm the exact PSU and approved accessory mapping rather than reusing a loose lead based on a familiar connector.
| Exact UK SKU | SF750 CP-9020284-UK | RM750x CP-9020199-UK |
|---|---|---|
| Physical format | SFX | ATX |
| Published dimensions | 125 mm width × 63.5 mm height × 100 mm length | 150 × 86 × 160 mm, listed order |
| Continuous output | 750 W | 750 W |
| Cable family | Type 5 | Type 4 |
| ATX version field | 3.1 | 2.4 |
A real compact case makes the format restriction concrete
Fractal Terra lists SFX and SFX-L PSU compatibility with a 130 mm maximum PSU length in its current product summary. The SF750 body’s 100 mm length leaves a 30 mm arithmetic difference from that stated length. That does not prove the complete cable route and neighbouring hardware fit, and the case’s detailed configuration must still be checked.
The cited RM750x is both an unsupported ATX form factor for that stated Terra list and longer than its 130 mm summary limit when considering the listed 160 mm dimension. A 750 W label cannot override either issue. An adapter bracket does not automatically resolve length, cable space or the manufacturer’s supported arrangement.
The rest of the system still determines electrical suitability
A physically accepted PSU is not automatically the correct electrical choice for every CPU and graphics card. Compare the exact component requirements, approved connectors and cable mapping. A newer ATX compliance label or larger output number does not substitute for those model-specific conditions.
The actual LC Power photograph shows a closed PSU body with a bundle of leads extending beyond it. That makes body size and complete connection space separate physical questions, but supplies no cable approval or pinout for either Corsair model. We provide no wiring modifications or PSU-opening instructions. Keep the unit closed and resolve uncertain cable identity through the manufacturer or a qualified supplier.
Compare complete UK quotations after the format is resolved
Record the PSU SKU, case and layout, approved cable set and all required hardware in the order. The actual 2017 installation shows a different fanless PSU above a motherboard and near drive bays and cabling. It illustrates shared space, not Terra fit or current Corsair dimensions. A case summary is a starting point; retain the detailed instructions for the actual arrangement.
No live prices, stock or independent efficiency and noise tests have been verified here. The Platinum and Gold branding on the respective pages is not converted into an invented electricity saving. The directly useful conclusion is physical and identifiable: these two 750 W products are different SFX and ATX enclosures with different dimensions and cable families, so the exact case and complete system requirements must agree.
