The USFF version of Lenovo’s ThinkCentre M91p packs a significant punch in a small package. Utilizing an Intel “S” low power processor and a 150W external AC power adapter, it’s also incredibly energy efficient.
April 4, 2012 by Lawrence Lee
Product | Lenovo ThinkCentre M91p Ultra-small Desktop PC |
Manufacturer | Lenovo |
MSRP | US$799 (base model) US$939 (sample configuration) |
Through the years Lenovo (formerly IBM) has developed a reputation for rock solid personal computer systems. Their ThinkPad line is particularly famous for its Spartan qualities that appealed to both business and home users alike. For the white collar masses who find themselves chained to desks and cubicles for much of the day, there is the ThinkCentre series, with the M91p being the current flagship model. To suit specific needs it actually comes in three different forms, a traditional bulky microATX tower, a slimmer low profile case, and an even tinier ultra-small form factor enclosure.
|
|
If the USFF version of the M91p looks familiar, it’s probably because they’ve recycled the case from last generation’s model, the M90p (the even older M58p also had a similar chassis). Like most PCs built for commercial use, it has a boxy no-nonsense shape with a matte black finish, giving off the impression that absolutely no fun is on the agenda. While its appearance is mind-numbingly dull compared to the many sleek home computers marketed to regular consumers, its dimensions are appealing to all. It takes up less than one square foot of space when placed horizontally and is only about three inches thick.
The hardware inside is also impressive, not compromising on performance despite the diminutive size. Not only does the USFF M91p utilize Sandy Bridge processors, they belong to Intel’s "S" line, low power quad core chips with a TDP of just 65W. As the M90p used dual core Clarkdale CPUs, the M91p is more powerful but doesn’t increase the energy footprint. Energy efficiency is a big selling point for corporate PCs as even a small power savings can be significant if there are a high number of systems in operation. The motherboard is also based on the Q67 chipset which supports advanced security and management features like Intel’s vPro and AMT (Active Management Technology) as it’s important to be able to lock things down on a business PC.
|
As the M91p is equipped with a 65W processor and lacks discrete graphics, the provided external 150W AC adapter is sufficient to run the entire system. Small desktops are typically powered by internal FlexATX units which aren’t as efficient, generate noise, and take up valuable space inside the chassis. Like most proper pre-built PCs, the machine ships with a simple mouse and keyboard. There’s an internal speaker as well so all you need to get it running is a display.
Lenovo ThinkCentre M91p Ultra-small Desktop: Specifications (from the product web page) | |
Processor | Intel Core i5-2500S (2.7GHz, 6M Cache) |
Operating System | Genuine Windows 7 Professional 64 |
Mechanical Package | Eco USFF 1×2, Intel Q67, (WW except Russia) |
Memory | 4GB PC3-10600 1333MHz SODIMM (1 DIMM) |
Graphics | Integrated Intel Q67 |
Storage | 500GB, 7200 RPM SATA |
Optical Drive | DVD Recordable (with DVD Playback & Burner Software) for Win 7 |
Networking | Integrated Gigabit Ethernet Intel Q67 |
Warranty | On-site 1 Year Part / 1 Year Labor |
Note: Component upgrades over the base configuration in bold. |
The base model of the M91p has an i5-2400S processor, 2GB of RAM, and a 250GB hard drive, so our sample’s configuration is a substantial upgraded. The i5-2500S in particular is a big step up, capable of hitting 3.7 GHz with Turbo Boost (the i5-2400S can only reach 3.3 GHz). It’s also a highly coveted chip that is not available in retail channels. Noticeably absent from the specifications are features like eSATA and USB 3.0, surprising as the latter is standard on most Sandy Bridge boards.
PHYSICAL DETAILS
The Lenovo ThinkCentre M91p’s shell is the same as the M90p, measuring 27.5 x 23.8 x 7.9 cm or 10.8 x 9.4 x 3.1 inches (L x W x H) and weighing 4.2 kg (9.2 lb). As the case is fairly compact there is room for only a single optical drive and hard disk, and one low profile PCI expansion card.
|
|
|
|
|
|
INTERIOR
An important aspect to consider when choosing an office PC is how convenient the machine is to service. The M90p was just about perfect in this regard, so we have little issue with the M91p recycling its design. It cleverly opens up like a clamshell without using any tools and because it’s a small case, the components are immediately accessible. You don’t have to grope your way through the interior of a big tower to disconnect cables, etc.
|
|
|
|
|
|
TEST METHODOLOGY
Software and Measurement/Analysis Tools:
- CPU-Z
to monitor CPU frequency and voltage. - CPUBurn
CPU stress software. - Prime95
CPU stress software. - FurMark
GPU stress software. - Cyberlink
PowerDVD 10 Ultra 3D Mark II to play MOV files and Blu-ray discs. - Real Temp
to CPU temperatures. - SpeedFan
to monitor system temperatures and fan speeds. - Seasonic
Power Angel AC power meter, used to measure the power consumption
of the system. - Infrared Thermometer to measure external the temperature.
|
Testing Procedures
If available, the latest motherboard BIOS is installed prior to testing. Certain services/features
like Indexing, Superfetch, System Restore, and Windows Defender are disabled
to prevent them from causing spikes in CPU/HDD usage. We also make note if energy
saving features like Cool’n’Quiet/SpeedStep or S3 suspend-to-RAM do not function
properly.
Our test is a simple one, determine the overall AC power consumption, noise level, and heat output and
at various states. To stress the CPU, we
use either Prime95 (large FFTs setting) or CPUBurn depending on which produces
higher system power consumption. To stress the IGP, we use FurMark, an OpenGL
benchmarking and stability testing utility.
Test Results
System Measurements | ||||||
System State | Temps | Power (AC) | dBA @1m | dBA @0.6m† | ||
CPU | HDD | Ext* | ||||
Off | N/A | 2W | N/A | |||
Sleep (S3) | N/A | 4W | N/A | |||
Idle | 34°C | 32°C | 27°C | 22W | 20 | 24 |
H.264 Playback | 35°C | 32°C | 26°C | 29W | 20 | 24 |
CPU Load | 69°C | 33°C | 30°C | 78W | 24 | 28 |
CPU + GPU Load | 78°C | 34°C | 32°C | 92W | 24 | 28 |
Ambient: 22°C, 10~11 dBA. *External temperature measured using an IR thermometer pointed at the hottest portion of the chassis. † We measure SPL at 0.6m for all devices meant to be used atop a desk, as it is more realistic a distance than the usual 1m. It also corresponds to the "seated user SPL" distance specified in the computer noise measurement standard ISO 7779. |
Both the Core i5-2500S processor and the included 150W AC power adapter are very energy efficient. The M91p to consumed an impressive 22W when idle and 92W on full load, far less than a desktop using a traditional internal power supply. The hard drive, despite being positioned just above the CPU heatsink stayed under 35°C throughout testing and the case didn’t heat up much either. CPU temperatures were not great on load, but that was to be expected given the system’s tight confines.
We were concerned that noise would be an issue, but the system wasn’t terrible loud considering the performance of the CPU and the form factor of the case. The machine generated 20 dBA@1m (24 [email protected]) at idle and during H.264 video playback, and 24 dBA@1m (28 [email protected]) on load. The BIOS lacks customizable fan control options and no tool we tried could monitor the fan speed, but the exhaust fan seemed to ramp up very gradually as the system heated up.
|
While the overall noise level was decent, the quality of the noise left much to be desired. At 0.6m inside our anechoic chamber we could detect an audible rattle and buzzing coming from the fan’s motor. Small, high speed, ball bearing fans aren’t typically smooth sounding, but it wasn’t solely responsible for the noise being generated. The system produced a noticeable hum caused by hard drive vibration passed onto the case; We could feel the exterior shaking slightly. The CPU/VRM circuitry also generated some coil whine, a high-pitched squeal that presented at idle only, disappearing once any type of CPU load was introduced. This too was audible at 0.6m but dissipated with distance.
Comparison vs. M90p
System Measurements | ||||||
System State | USFF ThinkCentre M91p (Core i5-2500S) | USFF ThinkCentre M90p (Core i5-650) | ||||
CPU Temp | dBA @0.6m | Power (AC) | CPU Temp | dBA @0.6m | Power (AC) | |
Idle | 34°C | 24 | 22W | 23°C | 24 | 40W |
H.264 Playback | 35°C | 24 | 29W | 32°C | 26 | 56W |
CPU Load | 69°C | 28 | 78W | 78°C | 30~31 | 95W |
CPU + GPU Load | 78°C | 28 | 92W | 85°C | 30~31 | 115W |
Ambient: 22°C, 10~11 dBA. *External temperature measured using an IR thermometer pointed at the hottest portion of the chassis. † We measure SPL at 0.6m for all devices meant to be used atop a desk, as it is more realistic a distance than the usual 1m. It also corresponds to the "seated user SPL" distance specified in the computer noise measurement standard ISO 7779. |
Compared to last USFF ThinkCentre sent to us by Lenovo, the M90p featuring the same case, the M91p is an environmentally superior machine. It runs cooler and quieter on load and uses substantially less energy thanks to the i5-2500S. The power consumption numbers are staggering, almost half that of the M90p when idle, and a 20% improvement on load. The CPU also has two more cores, so it’s significantly more powerful to boot.
CPU/GPU Performance
The i5-2500S is a rather rare CPU for sale to OEMs only and is not available through retail channels. It’s a 65W quad core Sandy Bridge chip with a 2.7 GHz clock speed that can be Turbo Boosted up to 3.7 GHz. Thus in single-threaded applications its performance is comparable to the i5-2500K, while multithreaded performance is closer to that of the i5-2400S (2.5 GHz, 3.3 GHz with Turbo Boost). It is equipped with the same integrated HD 3000 graphics processor as the 2500K. For performance analyses of these chips, please read our reviews listed below:
Hard Drive Performance
|
Though the Seagate 7200.12 line is a bit long in the tooth, the 500GB model had a respectable file transfer rate according to HD Tune. The 18.1 ms access time was very poor though, similar to what you would find on a "green" drive.
Pre-installed Software
Aside from the typical Windows bloatware like Adobe Reader, Bing Bar, Microsoft Silverlight, a trial edition of Office 2010, and a Norton Internet Security installer, the M91p came with Corel Burn.Now, Corel DVD MovieFactory, and a host of Lenovo system management utilities.
|
The ThinkVantage Toolbox is the star of this menagerie, tying everything together into a portal to a variety of system settings, diagnostics and miscellaneous information. What they’ve done is essentially pulled settings and menus native to Windows and put it all in one easy to find location and dressed it up. While we would like to say it adds something extra for the experienced PC user, it seems more of a tool for the neophyte rather than the IT professional performing maintenance or troubleshooting a problem.
Audio Recordings
These recordings were made with a high resolution, lab quality, digital recording
system inside SPCR’s own 11 dBA ambient anechoic chamber, then converted to
LAME 128kbps encoded MP3s. We’ve listened long and hard to ensure there is no
audible degradation from the original WAV files to these MP3s. They represent
a quick snapshot of what we heard during the review.
Each recording starts with ambient noise, then 10 second segments of product
at various states. For the most realistic results,
set the volume so that the starting ambient level is just barely audible, then
don’t change the volume setting again while comparing all the sound files.
- Lenovo ThinkCentre M91p at 0.6m distance
— idle/H.264 playback (24 dBA)
— CPU load/CPU+GPU load (28 dBA)
FINAL THOUGHTS
The Lenovo ThinkCentre M91p hits most of the relevant marks for an enterprise-class desktop PC. The Q67 chipset gives it advanced security and management features and the Core i5 "S" processor delivers high speed, quad core performance with truly impressive energy efficiency. The power savings over the Clarkdale-powered M90p with the same case were substantial. Though based on relatively recent hardware, the system does lack quite a few extraneous features like USB 3.0 and eSATA. It’s a powerful PC, but in many regards it’s rather basic.
Expansion is severely limited due to the form factor, so if you require a system with more versatility, the M91p also is available in two larger sizes depending on your needs. The USFF case is not new, being used previously with the M90p, but this is a good thing. It’s compact, takes little space on the floor or desk and perhaps most importantly, is incredibly easy to open. This last quality is simply magnificent making it extremely convenient to perform physical maintenance and upgrades. It’s the type of thing we wish was more common in consumer PC cases. Our only complaint about the design is how loosely the hard drive is secured.
While these types of systems aren’t typically designed for low noise operation, the M91p is reasonable in this department as the office/corporate environment generally has more ambient background noise than at home. We would recommend keeping it at a distance of one meter or greater or keeping under a desk though. The quality of the noise generated is worse than the total volume, especially at close proximity. The hard drive mount makes the entire case vibrate, the fan’s ball bearing motor has an unpleasant rattle, and the CPU/VRM circuitry emits coil whine when idle. The M91p is squarely pegged as a business PC, unsuitable for home use due to these noise issues and presence of premium chipset features that would likely go unused in non-corporate settings.
Custom Alternative to Lenovo ThinkCentre M91p (Base Configuration, US$799) | ||
Component | Model | Street Price* |
Processor | Intel Core i5-2400S | $200 |
Motherboard | Intel BOXDQ67EPB3 | $120 |
Memory | Crucial Rendition 2GB DDR3-1333 | $10 |
Hard Drive | WD Caviar Blue 250GB | $50 |
Optical Drive | Samsung SN-208BB Slim DVD Burner | $25 |
Case/PSU | Antec ISK 300-150 | $75 |
Keyboard/Mouse | Microsoft Wired Desktop 400 | $15 |
Speakers | Cyber Acoustics CA-2012 | $10 |
Operating System | Windows 7 Professional 64-bit OEM | $140 |
TOTAL | $645 | |
*Rounded to the nearest US$5. |
A common way to gauge the value of a pre-built machine is to see how its price stands up to that of a comparable custom system. We priced an equivalent DIY build to the M91p’s base configuration and found it to be cheaper by US$154. While this seems large, it’s actually fairly reasonable compared to most business PCs on the market. It’s also difficult to put a dollar value on the M91p’s slimmer, easy to open enclosure, and far superior warranty and support.
Our thanks to Lenovo
for the ThinkCentre M91p Ultra-small Desktop PC sample.
* * *
Articles of Related Interest
Logic Supply LGX AG150 Fanless Mini PC
Sapphire Edge HD3: AMD E-450 Mini PC
Viako Mini Letter ML-80 H61 Sandy Bridge Barebones PC
Serenity Mini, SPCR Edition by Puget Computers
Fanless Power Supply PC Build Guide
Aleutia H3-R Fanless Core i5 Media PC
* * *