OCZ question

[manveruppd]

So why is this PSU and the equivalent GamerXstream so cheap? They're £20 less than the next-cheapest PSU of equivalent wattage, and £20 less than OCZ 700-Watter. I've heard OCZ praised to the skies on these forums so I know it's not because they're some nasty "budget" PSUs.

On a related topic, is there a difference between the Stealth and the Gamer apart from the LED?

 

[Frame352]

So why is this PSU and the equivalent GamerXstream so cheap? They're £20 less than the next-cheapest PSU of equivalent wattage, and £20 less than OCZ 700-Watter. I've heard OCZ praised to the skies on these forums so I know it's not because they're some nasty "budget" PSUs.

No idea! At a guess, I'd say these two models are not modular maybe?

On a related topic, is there a difference between the Stealth and the Gamer apart from the LED?

From the OCZ website, looks like it's simply different specs, connectors etc;
http://www.ocztechnology.com/products/power_management/ocz_stealthxstream_power_supply
http://www.ocztechnology.com/produc...cz_gamexstream_power_supply-nvidia_sli_ready_

Also, the GameExtreme is NVIDIA SLI certified

 

[Mekrel]

So why is this PSU and the equivalent GamerXstream so cheap? They're £20 less than the next-cheapest PSU of equivalent wattage, and £20 less than OCZ 700-Watter. I've heard OCZ praised to the skies on these forums so I know it's not because they're some nasty "budget" PSUs.

On a related topic, is there a difference between the Stealth and the Gamer apart from the LED?

Thats because (and I really don't mean any offence to this forum when I say this) a lot (not all) people on here seem to just read reviews which basically hook the PSU to a system, run 3DMark and Orthos and say it did the job and looks pretty.

Most OCZ PSU's are based on the Epsilon unit, which has problems with ripple. Both HardOCP and JonnyGuru note that the episilon units have bad ripple, so bad that they go out of ATX spec of 120mv on the 12v rail.

Jonny had the same result on the GameXtreme PSU he tested, the Epsilon unit from FSP (who are the OEM that make the PSU for OCZ) and also had an OCZ exchange the unit - to which the replacement did the same.

They ain't Qtec PSU's no, but there are better PSU's out there. I find the QA of OCZ really bad when it comes to PSU's - they had to exchange a load due to units running 100% fan speed all the time.

Other units based on the Epsilon design such as the Zalman 600w PSU's don't have the ripple problem. Again, this only reflects OCZ's QA as being under par.

Things were satisfactory until test 3. During test 3, I started to see ripple on 12V1 and 12V2 that was nearly 100mV. By test 5, the ripple was 100mV on 12V3 and 12V4 and had exceeded 100mV on 12V1 and 12V2. By test 6, the ripple on 12V1 and 12V2 had exceeded 150mV.

ATX specification has an "allowance" for 120mV. Mind you, test 6 was very stressful, pushing the power supply to it's limits, but it doesn't change the fact that the ripple exceeded spec and this is the first power supply to date I have had do this.

What's wrong with too much ripple? Well, if the voltage fluctuates too erratically, it can over work other regulators used to provide Vcore to the CPU, GPU, etc.

A representative of OCZ did find my findings concerning and asked that I return the unit for an exchange. I did so, and in the interim I obtained an FSP Epsilon 600W. The 600W version of the power supply the OCZ GameXstream is based on. In testing that unit, I found a good deal of ripple as well. When a brand new GameXstream was finally returned to me, I immediately plugged it in and found the same results as the first sample.

Again, another Epsilon based GameXtreme 1010w PSU

Overall the DC Output quality of the GameXStream is disappointing given the lower powered Epsilon based unit we recently reviewed was not plagued by the noisy nature of the platform. Today, however the GameXStream 1010w was like the other members of the Epsilon line by starting off active and being almost out of specifications at only 50% load. At 75% load the ripple/noise of the unit was out of specification on the 3.3v/5v rails. This does not bode well for a system as system memory is powered off of the 3.3v. It has additionally been reported by other reviewers that at high loads the 12v rails were out of specification as well and indeed the unit even advertises the fact that it does not meet the ATX12v allowance of 120mV instead it is specified as being 140mV. Since our unit was unable to complete Test #4 we can not completely verify the 12v figures, however it should be noted that the 12v1 was around 100mV at both Test #3 and the Torture Test. Typically noise/ripple increase with load and I would expect this trend to continue with the OCZ GameXStream 1010w.

These guys actually hook PSU's up to mesuring stations to mesure true load at rated operating temperatures. Then use a oscilloscope to measure DC output quality.

 

[pastymuncher]

I think the ripple problem is fixed now. I read a review that used the same testing methods as those two and it was gone. I will have a look to see if i can find it again. If it was'nt fixed there is no way i would have got mine a couple of weeks ago. Mine is very quiet by the way so that must have been fixed as well.

As for the prices. OCZ has just bought PC Power and Cooling who make very high quality psu's so they could be shifting stock to make way for new models.

 

[manveruppd]

Hmm... this is getting interesting! Are you saying that this particular model is sub-par, or that ALL OCZ PSUs are inferior and should be avoided? They really are highly-thought of on here, it's interesting that they have these kinds of problems, and that they've been noted in sites as popular as HardOCP and people on here still reccomend them!

And I didn't know they bought PC P&P! That company really is considered the king in PSUs (unless that's another myth you can debunk?). Does this mean that OCZ is likely to start getting PCP&P to build their PSUs rather than FSP and their build quality will improve?

 

[Mekrel]

Hmm... this is getting interesting! Are you saying that this particular model is sub-par, or that ALL OCZ PSUs are inferior and should be avoided? They really are highly-thought of on here, it's interesting that they have these kinds of problems, and that they've been noted in sites as popular as HardOCP and people on here still reccomend them!

And I didn't know they bought PC P&P! That company really is considered the king in PSUs (unless that's another myth you can debunk?). Does this mean that OCZ is likely to start getting PCP&P to build their PSUs rather than FSP and their build quality will improve?

Some of their PSU's are ok, the ProXtremes are made by 3Y and these are alright units.

All I'm saying is, there are better units out there.

Also, I think all OCZs latest PSUs are multi rail, which isn't as good as having one beefy single rail. Intel 2.2 ATX spec says it's for safety reasons alone that multi rail exists - they think it's dangerous to provide more than 20amps over one rail.

Problem is it has been turned into a marketing gimmick of more rails = better. Problem is, if one rail gets to a certain amperage of around ~24amps (for most units) then the OCP will kick in a shut the unit down regardless of how much is being drawn from the other rails.

It's for these reasons alone I've gone for a Silverstone Olympia 60A on the 12v rail. Silverstone PSU's are amazing, even Kingpin uses the 850 model for most his benchmarks.

Apparently no! The PC P&C units will be untouched by OCZ and OCZ will still sell the rebadged OEM units. They are just selling PC P&C units through their distribution channels.