![[Head-to-Head] Ultra-Thin Watches | The Ultra-Thin Showdown: Richard Mille RMUP-01 Ferrari vs. BVLGARI Octo Finissimo Ultra COSC](https://blog.aristohk.com/wp-content/uploads/2026/08/20260807-144522.webp)
Throughout the modern history of haute horlogerie, the pursuit of “extreme thinness” has always been the ultimate stage for top brands to showcase their technical prowess. While advancing horological technology means the Richard Mille RMUP-01 Ferrari and the BVLGARI Octo Finissimo Ultra COSC are technically no longer the absolute thinnest watches in the world, it is undeniable that these two masterpieces—measuring a mere 1.75 mm and 1.7 mm thick, respectively—are highly representative milestones in contemporary ultra-thin watchmaking. Today, we conduct an in-depth breakdown of this ultra-thin duel.
The Ultra-Thin Arms Race
To recount the history of this ultra-thin showdown, we must first look back at BVLGARI’s profound heritage in this domain. Over the past decade, BVLGARI has risen to prominence in high watchmaking with its Octo Finissimo collection, consecutively breaking multiple world records across various complications, including minute repeaters, automatic watches, automatic tourbillons, and automatic perpetual calendars. By March 2022, the brand launched the Octo Finissimo Ultra, measuring just 1.8 mm thick, seemingly securing the ultra-thin throne.
However, the competition was far fiercer than imagined. Just a few months later, in July 2022, Richard Mille partnered with Ferrari to surprisingly unveil the RMUP-01 Ferrari. At just 1.75 mm thick, it successfully pulled ahead by a microscopic margin of 0.05 mm. Facing this technical challenge, BVLGARI, deeply rooted in the ultra-thin sector, did not back down. After two years of intensive R&D, they introduced the groundbreaking Octo Finissimo Ultra COSC in 2024. Not only did they further compress the overall thickness to 1.7 mm, but they also unprecedentedly obtained the Swiss Official Chronometer Testing Institute (COSC) certification, pushing this technical tug-of-war to a new climax.
The two brands demonstrated entirely different horological philosophies in their technical approach to extreme thinness. BVLGARI utilized the case back directly as the movement’s mainplate, crafting it from incredibly hard tungsten carbide, thereby eliminating the thickness of a traditional case. All movement components are spread horizontally on a single plane, maximizing the use of surface area. Conversely, Richard Mille adhered to traditional watchmaking concepts—retaining an independent movement and case structure. The movement of the RMUP-01 Ferrari is completely assembled independently before being housed within a Grade 5 titanium case. To achieve a thickness of 1.75 mm while maintaining a traditional structure, Richard Mille collaborated with the Audemars Piguet Le Locle manufacture to reinvent the escapement system, removing the traditional dart and safety roller to completely flatten the escapement architecture.
In-Depth Comparison
This microscopic duel, separated by a mere 0.05 mm, not only showcases two diametrically opposed watchmaking philosophies but also proves that extreme thinness and daily practicality can indeed coexist.
Dial Layout
In terms of dial layout, the two present extremely contrasting visual aesthetics. The dial of the BVLGARI Octo Finissimo Ultra COSC employs a separated layout similar to a regulator display. The hours and minutes are displayed on two independent titanium sub-dials, while the seconds are cleverly integrated between the hour and minute wheels. On the upper left of the dial sits a massive barrel, engraved with a highly modern Data Matrix code. A quick scan reveals all exclusive information and media related to the watch, allowing the wearer to delve deeply into BVLGARI’s watchmaking journey.
As for the Richard Mille RMUP-01 Ferrari, its layout exudes the functional aesthetics of a racing car dashboard. On the incredibly broad titanium dial, the time display is compressed into a tiny window at the top center, accompanied by a precise balance wheel structure beside it. The Ferrari Prancing Horse emblem in the lower right corner highlights the partnership between the two brands. To maintain its slim profile, the watch discards the traditional crown. Winding and time-setting are executed directly on the dial: the upper left houses the function selector, while the lower left is used for winding and setting the time.
Case and Strap
Regarding case design, the BVLGARI Octo Finissimo Ultra COSC continues the brand’s iconic octagonal geometric aesthetics. With a diameter of 40 mm, the entire watch is infused with a strong sense of architectural geometry and Italian elegance. The brand utilizes a highly rigid tungsten carbide baseplate paired with a titanium bezel and lugs, equipped with an ultra-thin integrated titanium bracelet measuring just 1.5 mm thick. The folding clasp is ingeniously hidden within the links, fitting like a second skin. To cover the expansive dial while controlling thickness, BVLGARI compressed the sapphire crystal to an extreme limit of 0.3 mm, making this watch even thinner than the Octo Finissimo Ultra introduced in 2022. Naturally, for a watch only 1.7 mm thick, a traditional crown would be too small to operate properly; thus, the brand embedded two horizontal knobs on the sides of the case—one for winding and the other for setting the time.
Conversely, the Richard Mille RMUP-01 Ferrari breaks away from the brand’s signature three-dimensional tonneau design, adopting a horizontally extended, ultra-thin tonneau silhouette. Measuring 51 mm x 39 mm, it features a Grade 5 titanium case. To carve out the ultimate space for thinness, Richard Mille completely abandoned the traditional large crystal covering the entire dial. Instead, they embedded two minuscule sapphire crystals over the time display and the balance wheel, with thicknesses compressed to 0.45 mm and 0.2 mm, respectively. Paired with a custom-designed integrated rubber strap, the total weight of the entire watch (including the strap) is only about 30 grams, making it exceptionally lightweight.
Movement Performance
In the core movement technology of ultra-thin watches, the two brands delivered vastly different engineering answers. BVLGARI’s BVL 180 manual-winding movement lacks a traditional movement baseplate, as the tungsten carbide case back itself serves as the mainplate. All movement components spread horizontally on a single plane, maximizing surface space utilization. Within a space of just 1.7 mm, it still provides a 50-hour power reserve and is COSC chronometer-certified. This proves that no matter how thin the watch is, BVLGARI can maintain stable torque output.
Richard Mille, however, adhered to traditional watchmaking concepts. The RMUP-01 Ferrari retains an independent dual-layer structure of movement and case. The RMUP-01 manual-winding movement itself is only 1.18 mm thick, boasts a 45-hour power reserve, and is completely assembled independently before being housed in the case. To achieve extreme thinness while preserving a traditional structure, Richard Mille collaborated with Audemars Piguet Le Locle to reinvent an ultra-flat escapement system. Because the dart and safety roller in a traditional escapement take up substantial vertical space, the engineering team unprecedentedly removed them, integrating the banking function directly into the anchor fork to create a patented ultra-flat escapement. Coupled with the use of Grade 5 titanium for the baseplate and bridges, it can withstand shock accelerations of up to 5,000 g’s. This means it is not just a technical statement, but an ultra-thin watch you can truly wear while playing sports.
Which One Belongs in Your Collection?
Objectively speaking, there is no superiority between these two watches, only a difference in style and philosophy. For collectors who favor pure architectural aesthetics, integrated design, and an ultimate pursuit of precision, BVLGARI is undoubtedly the perfect paradigm of modern ultra-thin watchmaking. However, if you seek avant-garde mechanical aesthetics, love racing culture, and appreciate a disruptive mindset that breaks traditional norms, the Richard Mille RMUP-01 Ferrari is absolutely the choice for you.
