CPU bottleneck ???

[fussy-p]

Hi all,

 

Hoping someone will able to help me get an idea as to how much of a bottleneck my laptop CPU would be in the following scenario:

 

My laptop (Dell Latitude 7390) has:

 

   CPU: Intel 8th Gen i7 8650U (8M cache, quad, 1.9GHz)

   RAM: 16GB 2133MHz

   SSD: M.2 512GB PCIe NVMe

 

It also has TB3 (4x lanes) and I've confirmed with a Dell customer service rep that it would indeed support an external graphics enclosure.

 

I want to buy a Razer Core X eGPU enclosure and put either an Nvidia RTX 2070 or 2080 in it.

 

 

I realize the CPU would be the bottleneck in this instance but by how much? 

 

On a scale of 'it's not that big of a deal - games will still run great' to 'the CPU would be so limiting in this instance - don't bother - just buy a desktop' -- what are peoples thoughts?

 

As a further question - is an RTX 2080 too much for this setup? Is the 2070 more appropriate? Or would the 2080 show proper performance benefits? I intent to run a maximum of 1440p 144Hz but will most likely just run a 1080p setup.

 

 

Also getting a desktop would be great, but this laptop was free from work and I have full permissions to run an eGPU with games etc.

 

Thanks in advance everyone!

 

 

[Crunchy Dragon]

The Thunderbolt 3 interface will bottleneck the GPU a lot more than your CPU will.

 

Most GPUs can't perform very well for gaming at just PCIe x4.

[Mira Yurizaki]

It's likely the CPU will bottleneck the GPU more, not the Thunderbolt interface, depending on what resolution you're playing at.

 

Otherwise at worst, you may have 10% loss in performance at 1080p as TechPowerUp tested it for an RTX 2080 Ti (https://www.techpowerup.com/reviews/NVIDIA/GeForce_RTX_2080_Ti_PCI-Express_Scaling/6.html). Though for an RTX 2080, the loss will probably be lower.

[badreg]

Unless you have a huge need to game on the go, save the $299 that it costs for the eGPU enclosure and put it towards a desktop platform. The laptop is great for business use, but not really designed for gaming.

 

If you insist on pursuing this further, I would first run AIDA64 to test the thermal solution to see how high of a turbo your CPU can sustain. It has a base frequency of 1.9Ghz, but an all-core turbo clock of 3.9Ghz, so real world performance is dependent on the cooling. Run the AIDA64 stress test for 30 minutes and see what kind of clocks you can sustain. If it stays above 3.0Ghz consistently, then you might be fine with an eGPU up to a GTX 1080 / RTX 2070. A more powerful GPU will be pointless as the PCIe 3.0 x4 becomes the bottleneck.

[fussy-p]

Thanks for all the replies everyone

 

18 hours ago, badreg said:

Unless you have a huge need to game on the go, save the $299 that it costs for the eGPU enclosure and put it towards a desktop platform. The laptop is great for business use, but not really designed for gaming.

 

If you insist on pursuing this further, I would first run AIDA64 to test the thermal solution to see how high of a turbo your CPU can sustain. It has a base frequency of 1.9Ghz, but an all-core turbo clock of 3.9Ghz, so real world performance is dependent on the cooling. Run the AIDA64 stress test for 30 minutes and see what kind of clocks you can sustain. If it stays above 3.0Ghz consistently, then you might be fine with an eGPU up to a GTX 1080 / RTX 2070. A more powerful GPU will be pointless as the PCIe 3.0 x4 becomes the bottleneck.

@badreg - I guess in this instance it's not as straight forward as just getting a desktop PC. I'm very aware that the desktop solution would ultimately be the best in terms of performance ... but I have a decent laptop with TB3 (4 lanes) provided for no cost. I'm trying to roughly determine how much of a hit games would take with this laptop CPU + eGPU combo vs a desktop. If it were say, 75% of the performance of what I could get by spending $1000 on a desktop then that's worth it for me. If people were to come back and said that the CPU is waaaay too limiting in this instance and I'd be getting like 40-50% of the performance of a $1000 desktop then the writing would be on the wall and I'd just buy a desktop.

 

The laptop also has a few other advantages though. Having the one unit that does both work when I'm mobile and at home + gaming for when I'm at home is pretty awesome. 

 

Also from what you're saying it sounds like a RTX 2070 is a more appropriate fit for the overall configuration. I thought this might be the case as the RTX 2080 seems like overkill.

 

Also I'll give that AIDA64 test a go and report back the results.

[badreg]

2 minutes ago, fussy-p said:

I'm trying to roughly determine how much of a hit games would take with this laptop CPU + eGPU combo vs a desktop. If it were say, 75% of the performance of what I could get by spending $1000 on a desktop then that's worth it for me. If people were to come back and said that the CPU is waaaay too limiting in this instance and I'd be getting like 40-50% of the performance of a $1000 desktop then the writing would be on the wall and I'd just buy a desktop.

You won't really know for sure until you do the stress test. If you can sustain clocks above 3.0Ghz, then you may well get to that 75% mark. On the other hand, if you only get 1.9Ghz, then we're looking more like 40-50%.

 

However, even in the best case scenario, you'd be spending $800 for somewhat compromised performance on a machine that you don't own. Why not consider something like Shadow? You can almost pay for an entire year for what the eGPU enclosure would cost.