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Lenovo Flex 5 5700U First Impressions

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Zerileous

Senior Member
Joined
Jun 21, 2002
So I got a 2 in 1 to use for graduate school. The use case is read and mark up electronic text books, participate in online "zoom" style classes as well as asynchronous classes and take notes, travel with me from place to place, and do all the normal school computer things. First impressions are pretty good, keyboard is great (lenovo inherited this from IBM imho) but I'm still glad for the Keychron for heavier duties. The 14" screen is fine not the best but looks pretty good. CPU is decent, 1700x power in a 3 1/3 lb laptop. The iGPU seems pretty stripped down though, which is fine as this isn't a gaming machine.

Things I don't like: EDIT: The LPDDRx runs at the rated speed of 4266MTs (reported as 2127MHz in CPU-Z. Unfortunately this does cause the IF to drop to 2:1 and I wonder if it would be possible to run 3600 1:1 with tighter timings. The soldered LPDDR is super slow. Even my Dell work laptop runs 2600MTs so running Zen2 at 2100MTs CL40 really hamstrings the processor. The fan spins up during light loads in all but the lowest power mode. It runs a bit warm as well. It seems like AMD may be lagging behind Intel in low power states (even before we get into e-cores and p-cores), as my 10th gen work laptop never makes a sound, although in fairness I've never run benchmarks on it either. On the plus side, the fan just makes a low pitch wooshing noise, no whining typical of some laptop fans.

TLDR: Overall I think it's pretty incredible what you can get for a $600 sale these days. I wish I could have one fancier, but ultimately this is a utilitarian purchase and I think it will satisfy my needs.
CPUz.png PXL_20230407_155351441.jpg
There are 3 different power modes (and of course they perform differently on and off AC power). I'm going to call them Leaf, Snowflake and Turbo. Leaf is the low power mode, it automatically dims the screen for battery life, but I think it is the most reasonable setting for productivity and browsing, you just have to turn the screen back up yourself. Snowflake is supposed to be a quieter performance mode, and Turbo is all it's got. I only ran Cinebench R23 for 2 minute cycles because I didn't want to spend too much time on it. The single core test was set to 1 minute (ensuring just a single run). Also there seems to be an imposed single core limit of about 3500MHz on battery power, even though HWiNFO64 doesn't report this.

Battery Turbo: Here the 5700u beats the 1700x with 9091 points. Max CPU temp 82.6c. Package power 40W
turbo.jpg Battery Snowflake: Score roughly 400pts to 8685. Temp 72.1c, package power 37W
snowflake.jpg
Battery Leaf: R23 score drops all the way to 7583, Temp 59.3c, package power 18W
leaf.jpg
Due to the significantly lower power usage and temperatures, I think the Leaf mode is the best for most unplugged tasks. Doubling the power limit to Snowflake gets a sizeable performance bump of 1100 points but probably only for multi threaded workloads. You can definitely notice the battery single core speed limit doing things like unzipping a file. I didn't do a lot of single core testing because it takes so long, but if you're going to be doing stuff like extracting zip files, I would suggest based on unzipping R23 to use AC power and turbo mode if available.

AC Turbo: 9082 points, 90.8c, 47W. This could definitely be run to run variance, but IMHO the extra 7 watts just increases the temperature and probably is limiting performance at this speed.
AC.jpg AC Snowflake: 8974 points, 72.3c, 45W. There's obviously more going on here as this performs slower and cooler than the 40W battery turbo mode. At this point though I've done enough testing to figure out how I want to use the power modes.
ACSnowflake.jpg
Single Core AC Turbo: 1240 points, 76.0C and package power of 28W. CB is comparing it to the 7700k. Here we actually see the CPU boosting to 4.3GHz finally.
ACSC.jpg
In summary the CPU rivals flagships of 6 years ago, I think that's pretty dang good and certainly adequate for what I need. Keeping in mind this is a Zen2 part and offered at a very approachable budget.

Now for the most important question, will it run Crysis? Ehh, not really. A heaven run at 1507x924 (I goofed and chose "system" getting a strange resolution. The desktop reports a native resolution of 2240x1400.) Ultra quality, tessellation extreme and 8xAA yields an average FPS of 18.7. But can it at least outperform an 8 year old laptop with a GTX960M. Nope that system yielded an average of 26.9fps at a slightly lower 1440x855 resolution. I won't be gaming anyway, but I was curious what the Vega iGPUs could do in this application. We all know Vega needs power and this is a low power application, and we see expectedly low performance.
HeavenAC.jpg
 
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