Is Gamemax 1050W 80 Plus Silver Modular GP-1050 a good PSU?
NO, it's not a very good high-quality power supply unit, and Gamemax is not a trustworthy/reputed PSU brand, Why do need 1K WATTS PSU in the first place ?
Try to grab some other MODEL. I would recommend you to get the following PSU models and brands. These are high quality units. Look for similar SKUs.
SEASONIC PRIME, and Prime Ultra, or
FOCUS Plus GOLD, Focus Plus Platinum.
CORSAIR AXi, RMi,
RMx 550/650W, SF, HX 2017, HXi.
FSP - Hydro PTM 550/650W.
Cooler Master - MasterWatt Maker MiJ, V series 550/650W.
Antec - High Current Pro, High Current Platinum, Earthwatts Pro Gold, HCG Gold.
Super Flower - Leadex Gold II.
be Quiet! - Dark Power Pro 11, Straight Power 11, Dark Power Pro P10.
EVGA -Supernova G1+, GQ, P2, T2, G2, B2, BQ =>750.