Always read the label

A customer called me up the other day to tell me that the LabVIEW application I wrote for him several years ago needed to be updated for the latest Intel processors.

“Oh really?” I asked. “What feature of these new processors am I not taking advantage off?”

“No No, nothing like that, It’s just running really slowly on our brand new i7 laptop” he informed me.

“Really, that’s odd. Which i7 did you get ?” my interest growing by the second.

“The new one, it’s 4.0GHz……..definitely not an i3 or i5, we wanted the best and got a great deal. It was only 400 bucks”

Now my suspicions really did take over, I asked him to go to Device Manager and get me the system information, specifically the CPU model.

“I told you it was an i7, Its a i7-7Y75″ he responded.

BINGO !!!!

Unfortunately, as I would go on to explain to him, my customer had fallen victim of cleverly inconsistent marketing.

His processor is what is known as a Y-series (or Core M) processor. A CPU with a TDP of only 4.5W

In layman’s terms the thermal design power (TDP), sometimes called thermal design point, is the maximum amount of heat generated by a computer chip or component that the cooling system in a computer is designed to dissipate under any workload. The higher the TDP, the higher a computers ability to work under high load for prolonged periods of time.

Up until recently the badging of CPU’s as i5 and i7 was reserved for 15W (U-series) dual-core CPU’s as found in most ultrabooks such as the Dell XPS 13 or MacBook Air or 47W (HQ series) Quad Core processors such as those found in the MacBook Pro 15” and Dell XPS 15.

Core M CPU’s running at 4.5W were branded M3, M5 and M7 to differentiate and these could typically be found running in tablet devices as they can be passively cooled with no need for a fan.

With the advent of Intel’s 7th generation Kaby Lake processors, Intel decided to apply the branding i5 and i7 to all their offerings with some i5 and i7 Y-series devices appearing in laptops. Such a laptop had been purchased in this case.

Now, don’t get me wrong, Y-series CPU’s are not a bad thing. They consume little power and generate little heat and for short bursts of activity, they perform well. They’re targetted at productivity work such as email or word processing. Under Sustained, higher loads, the CPU must throttle to a lower clock speed (often 1.0 GHz or lower) in order to prevent overheating. As such they’re not ideal for the long-running continuous data analysis tasks that my customer was attempting.

They’re certainly not designed for software development using modern IDEs or running Virtual Machines.

Even U-series devices (15 watts) are best avoided. If you’re doing serious work you really need serious tools, a 45 Watt i5 or i7 will see you right for many many years and is money well spent.

The decision to go i5  or i7 really depends on how deep your pockets are. Intel uses performance binning to classify their devices, sure there are some minor feature difference (mainly between i3 and i5 rather than i7) but the analogy I like to use when comparing is i5 or i7 is travelling in a car. The i5 is a minor road, the i7 the freeway. Sure you can do 80 Mph on either but the ride will be smoother and less prone to crashing on the freeway!

So there you have it. Don’t be fooled by marketing, all i7 CPUs are not created equally. Understand your needs and ALWAYS read the label.

See you next time.

Chris