Definition: Given an Amazon customer review, write a title for the review. The preferred titles are under fifteen words.
Input: I'm of two minds about this power supply. Professional reviews complement the power delivery characteristics, and if mine lived in a server closet, I'd probably rate it five stars. I'm pulling back two because both my TX650 V1 (2010) and TX650 V2 (2013) exhibit coil whine under some loads. Coil whine occurs when copper coils resonate at an audible frequency. The resonance is natural, though ordinarily dampened or designed to occur above 20 KHz. It's harmless except to your sanity. My V1 was fine for two years, but eventually began to squeal at idle. The replacement V2 squeals during network transfers. UPDATE: As does the TX550M. I wish I could blame the system; a Cooler Master Silent Pro 600M and Seasonic G 450 work just fine.<br /><br />SUPPORT:<br /><br />Support is solid at Corsair, but I had some initial trouble taking advantage of the 5-year warranty. Contact methods include an online RMA form, a phone number, and, if you can find it, a hidden email feedback form. Turnaround times for a conventional RMA are measured in weeks. Corsair will do advance RMAs (wherein they send you a replacement first with a credit card hold and you then send yours back), but this is not possible to arrange with their online form.<br /><br />Calling them leads to a phone tree. When I first called, the phone tree ran in circles, eventually to a full voicemail box. Using the email feedback form netted an email telling me to use the same phone tree. I was later informed by email that this was a result of their 'Holiday' schedule where the entire office leaves for a week. This information appears nowhere; you're just meant to infer it when no one picks up.<br /><br />It took three phone calls to set up an advance RMA. Disconnections occurred even during in-office transfers. Hold times were two to fifteen minutes at 1PM on a weekday. The process aside, support ultimately upgraded me to a superior unit and provided return shipping labels, so I'm only out time. They definitely stand behind their product.<br /><br />PERFORMANCE:<br /><br />When my V1 was new, it was effectively silent and, at a Bronze rating, moderately efficient. Gold-rated units are 5-6% more efficient, which can result in significant yearly savings ($10-$25) if your load is near rated capacity around the clock. It continues to function even while emitting nasty noises, so I can't knock the reliability.<br /><br />Most power supplies have two general characteristics: they're most efficient at half-load, and half-load is when their fans start to ramp up. If you want a silent PSU, your maximum load should be no more than 60% of rated capacity. A Core i7 quad using integrated video will idle around 40W and draw up to 150W at full load. A mid-range ($200) graphics card will add 15W to the idle and 90W to the max load. A high-zoot or dual-chip graphics card ($400+) can double or triple both numbers. Overlocking can bump the load total by 25%.<br /><br />Because efficiency trails off rapidly below 20% load, and most systems spend most of their time at idle, it's best not to buy capacity well in excess of your needs. Naturally, this conflicts with the silence objective, so it's a bit of a trade-off with Bronze-rated units. Gold units preserve more efficiency at low loads. Some PSUs aren't capable of silence at any load. Seasonic (the designer and builder of the TX series) is better on that front; they use quiet fans and a fan power profile that keeps the fan idling, or entirely off in some cases, at low loads.<br /><br />The TX650 is designed for a system with a quad chip and dual-mid-range graphics cards. Here's how the numbers play out relative to, say, a Seasonic S12-380, also a Bronze unit:<br /><br />0.2 * 650 = 130W<br />0.5 * 650 = 325W<br /><br />0.2 * 380 = 76W<br />0.5 * 380 = 190W<br /><br />Typical integrated video PC:<br />idle: 40W<br />max: 150W<br /><br />Same PC with a mid-range graphics card:<br />idle: 55W<br />max: 240W<br /><br />In all cases, the first PC will be better with the lower-capacity power supply. It'll run more efficiently and it'll still be silent. The other system will put you to the choice: do you care more about fan noise at full load or efficiency at idle?<br /><br />Here's the load ballpark for each component:<br /><br />Quad CPU: 10W idle, 100W sustained<br />Motherboard: 15W-50W<br />Hard disk: 15W spinup, 2W idle, 7W sustained<br />SSD: 1W idle, 5W sustained<br />Optical: 1W idle, 10W sustained<br />Video card: 15W-25W idle, 70W-250W sustained<br />RAID card: 25W<br />NIC/sound/peripheral card: 10W<br />120mm fan: 3W<br /><br />FEATURES:<br /><br />This particular 650W TX is not a modular power supply. Modularity means that some or all cables are attached separately so you can pick and choose what you need. The more wattage and the more concerned you are with a clean build, the more important this feature is.<br /><br />With the semi-modular TX550M, modularity was no great help. Any system liable to require that wattage will use most or all of the available cables. The TX650 is something else; it has four cables devoted to molex and SATA plugs and two more to PCIe. The TX850 has an additional two PCIe. Unless your system has a dozen hard drives, at least a few will end up behind the motherboard tray.<br /><br />Lack of modularity can make for a bargain. The TX650 goes for as little as $50 after rebates. For a Bronze supply of this wattage with this warranty, that's very compelling.<br /><br />The cable sleeving for the three TX and HX copies I received could be improved. The sheath was loose (looking and feeling like a shedding snakeskin) on some cables and gluing wasn't completely hidden.<br /><br />COIL WHINE:<br /><br />If your unit whines, you have two options: RMA it or change the system power profile. Disabling EIST and the C1/C3/C6 halt states in the BIOS significantly reduced my coil whine. Idle power use went up 10-15W. Running Prime95 in the background eliminated the whine entirely. With my Core i7 quad, a single Prime95 thread at 11% CPU usage added 40W of idle power use, more than enough to kick the PSU above the power profile that caused noise. For reasons of performance and efficiency (40W of extra power in a 24/7 machine costs about $50 a year), I consider Prime95 a stop-gap solution until a replacement PSU arrives.<br /><br />IN SUM:<br /><br />In a stacked system, this TX650 would be a wonderful PSU. Power delivery is exemplary and you won't have the odd acoustics for which I've docked two stars. Systems without powerful graphics cards will do better with lesser-rated models.er with the lower-capacity power supply. It'll run more efficiently and it'll still be silent. The other system will put you to the choice: do you care more about fan noise at full load or efficiency at idle?<br /><br />Here's the load ballpark for each component:<br /><br />Quad CPU: 10W idle, 100W sustained<br />Motherboard: 15W-50W<br />Hard disk: 15W spinup, 2W idle, 7W sustained<br />SSD: 1W idle, 5W sustained<br />Optical: 1W idle, 10W sustained<br />Video card: 15W-25W idle, 70W-250W sustained<br />RAID card: 25W<br />NIC/sound/peripheral card: 10W<br />120mm fan: 3W<br /><br />FEATURES:<br /><br />This particular 650W TX is not a modular power supply. Modularity means that some or all cables are attached separately so you can pick and choose what you need. The more wattage and the more concerned you are with a clean build, the more important this feature is.<br /><br />With the semi-modular TX550M, modularity was no great help. Any system liable to require that wattage will use most or all of the available cables. The TX650 is something else; it has four cables devoted to molex and SATA plugs and two more to PCIe. The TX850 has an additional two PCIe. Unless your system has a dozen hard drives, at least a few will end up behind the motherboard tray.<br /><br />Lack of modularity can make for a bargain. The TX650 goes for as little as $50 after rebates. For a Bronze supply of this wattage with this warranty, that's very compelling.<br /><br />The cable sleeving for the three TX and HX copies I received could be improved. The sheath was loose (looking and feeling like a shedding snakeskin) on some cables and gluing wasn't completely hidden.<br /><br />COIL WHINE:<br /><br />If your unit whines, you have two options: RMA it or change the system power profile. Disabling EIST and the C1/C3/C6 halt states in the BIOS significantly reduced my coil whine. Idle power use went up 10-15W. Running Prime95 in the background eliminated the whine entirely. With my Core i7quad, a single Prime95 thread at 11% CPU usage added 40W of idle power use, more than enough to kick the PSU above the power profile that caused noise. For reasons of performance and efficiency (40W of extra power in a 24/7 machine costs about $50 a year), I consider Prime95 a stop-gap solution until a replacement PSU arrives.<br /><br />IN SUM:<br /><br />In a stacked system, this TX650 would be a wonderful PSU. Power delivery is exemplary and you won't have the odd acoustics for which I've docked two stars. Systems without powerful graphics cards will do better with lesser-rated models.

Fine performance, coil whine