All the king's horses and all the king's men cannot fix the trouble Intel has gotten itself into with the fractured re-branding effort behind its 7th-gen Core (Kaby Lake) processors. The new branding scheme is somewhat confusing because it discards the previous "m7" and "m5" nomenclature for Intel's low-power SKUs and brands them as "i5" and "i7" parts.
This will surely confuse shoppers, but the disappointing news is that the muddy branding waters hide a deeper undercurrent of obfuscation. OEMs can restrict Kaby Lake TDPs, which adjusts performance, into lower settings that extend below the advertised 4.5W and 15W power ranges. By the same token, Intel also allows vendors to adjust the TDP settings to exceed the normal specifications, which means there is an equal (though less likely) chance that the processors will feature higher-than-normal specs.
Intel has not defined a steadfast rule that requires OEMs to disclose the TDP settings on their packaging or in the marketing materials, which means you could be playing the silicon lottery when you purchase a laptop or 2-in-1. Let's untangle the web of confusing branding and dive into the deeper topic of TDP adjustments.
The Skewed SKU Branding
Whereas Intel used "Core m" nomenclature for its 4.5W Skylake chips, the 4.5W Kaby Lake SKUs bear the "i5" and "i7" branding that was used for 15W and higher Skylake parts. Only the lowest-end Core m chip in the Kaby Lake family, the m3, retains the same branding across both generations. Some proclaim the move to i7 and i5 branding is vague, at best, and doesn't help the "normal" customer discern between the 4.5W and 15W processors.
Perhaps more troubling is that vendors can configure the TDP either above or below the 4.5W setting. For instance, the Y-Series processors feature configurable TDP (cTDP) that includes a 3.5W "Down" setting, in addition to a 4.5W "Nominal" and 7W "Up" setting.
The vendors can select the various TDP ranges either statically or dynamically. Intel describes the feature in its launch-day documentation;
With Configurable TDP, the processor is now capable of modulating the maximum sustained power vs. performance. Configurable TDP thus provides design and performance flexibility to control system performance based on the cooling capability and usage scenarios. For example, a detachable Ultrabook may need more performance when used in a full clamshell mode (vs. tablet mode), or when balanced performance is needed in a quiet conference room setting.
A static 3.5W setting will allow the device to fit in smaller devices due to the lowered thermal envelope, and it will also boost battery life (which is the primary reason vendors adjust TDP). Unfortunately, this permanent setting lowers performance significantly, and the vendor is not required to disclose the TDP configuration, so many do this with little fanfare. The end user cannot adjust the statically-assigned TDP value. A vendor could also choose to manufacture a beefier device that trades battery life for more performance. This technique would boost the 4.5W processor up to 7W, but one could naturally assume the vendor would emblazon this enhancement on the packaging.
Dynamic TDP indicates that the device can employ on-the-fly cTDP adjustments based on sensor feedback, such as device orientation or temperature sensors. Dynamic cTDP adjustments are helpful to throttle performance when the device is hot, such as outside on a sunny day, which will help keep the chip within a safe thermal envelope. As stated in our recent Kaby Lake debut article:
The "skin" temperature sensors allow the device to detect and adjust frequencies, and the device can choose to stay in a Turbo Boost state for longer periods of time based upon the thermal headroom. Accelerometers also allow the device to adjust performance based on device orientation. For instance, the device will switch to a higher-power mode when it is in a static 45-degree orientation (which indicates docking), as opposed to a 90-degree orientation, which indicates a user is holding it.
AMD also allows vendors to adjust the TDP range of the Summit Ridge and Bristol Ridge APUs, though it's unclear if it supports dynamic adjustments. AMD encountered some customer pushback when it originally added the feature because OEMs did not disclose the actual TDP settings. The company reigned in the configurable TDP range with its newest APUs to discourage misleading adjustments.
|Y-Series Processors||7th Gen Core i7||6th Gen Core m7||7th Gen Core i5||6th Gen Core m5||7th Gen Core m3||6th Gen Core m3|
|Socket||FCBGA 1515||FCBGA 1515||FCBGA 1515||FCBGA 1515||FCBGA 1515||FCBGA 1515|
|Base Frequency (GHz)||1.3||1.2||1.2||1.1||1||0.9|
|Max. Single-Core Frequency (GHz)||3.6||3.1||3.2||2.7||2.6||2.2|
|Max. Threaded Frequency (GHz)||3.4||2.9||2.8||2.4||2.4||2|
|Graphics||HD Graphics 615||HD Graphics 515||HD Graphics 615||HD Graphics 515||HD Graphics 615||HD Graphics 515|
The Kaby Lake U-Series processors also feature the same configurable TDP range, albeit to a larger extent. The "Down" setting brings TDP down to 7.5W, and it also features "Nominal" 15W and "Up" 25W profiles. The i7 and i5 branding remain the same.
|U-Series Processors||7th Gen Core i7||6th Gen Core i7||7th Gen Core i5||6th Gen Core i5||7th Gen Core i3||6th Gen Core i3|
|Socket||FCBGA 1356||FCBGA 1356||FCBGA 1356||FCBGA 1356||FCBGA 1356||FCBGA 1356|
|Base Frequency (GHz)||2.7||2.5||2.5||2.3||2.4||2.3|
|Max. Single-Core Frequency (GHz)||3.5||3.1||3.1||2.8||N/A||N/A|
|Max. Threaded Frequency (GHz)||3.5||2.6||3.1||2.4||N/A||N/A|
|Graphics||HD Graphics 620||HD Graphics 520||HD Graphics 620||HD Graphics 520||HD Graphics 620||HD Graphics 520|
Staving Off The Wolves
Intel probably had the inclination that discarding the m7 and m5 branding would be the source of some consternation, so the company made a change to the Intel Core badges that are on the outside of the end user products. In the past, there was no indication of which generation of the processor was inside the device, but the new branding scheme brings the "7th Gen" moniker to the badge.
This might be helpful if a seventh-generation 4.5W i5 were comparable to a seventh-generation 15W i5 processor, but they aren't. Also, there isn't even a sixth-generation 4.5W i7 or i5 in existence, so it actually clarifies nothing.
Intel already has a somewhat confusing delineation between its "generations" branding and codenames, such as "Kaby Lake." For the record, Intel does not specifically market devices with the codename in an attempt to alleviate the confusion, but it actually just confuses the end user even more. Is it a "7th-gen Core" or a "Kaby Lake Core?" Well, confused customer, it's both.
Bringing the delineated 4.5W and 15W i5 and i7 branding into the picture just creates more confusion, and it does nothing to help us determine the actual cTDP setting.
The cTDP feature is useful, particularly for dynamic adjustments, but unfortunately OEMs can potentially abuse the feature. Because there isn't a requirement for the vendor to disclose the setting, you will have no idea if the device you just bought is even running at full speed. Clarification will require a trip to the vendor's detailed specs, and in some cases, a direct inquiry.
The new branding makes it a whole lot harder for the average user to determine just what Intel is inside (as it were), and the cTDP settings make it even harder to determine how fast it is.
Side note: Intel provided performance data of a few of its new SKUs, which were tested at various cTDP settings. Feel free to peruse the two images below to see the difference in performance. Unfortunately, Intel did not provide performance measurements with the restricted TDPs.