[CentOS] Problem with graphics on latest CentOS 6

The thread "Problems with kernel-3.10.0-693.5.2.el7.x86_64” reminded me that I have a similar problem but on the latest CentOS 6 kernel I’ve been meaning to report.  Here is the relevant system information:

Linux ssg003.bose.com 2.6.32-696.13.2.el6.i686 #1 SMP Thu Oct 5 20:42:25 UTC 2017 i686 i686 i386 GNU/Linux

00:02.0 VGA compatible controller: Intel Corporation Device 5912 (rev 04) (prog-if 00 [VGA controller])
        Subsystem: Dell Device 07a2
        Flags: bus master, fast devsel, latency 0, IRQ 11
        Memory at f6000000 (64-bit, non-prefetchable) [size=16M]
        Memory at e0000000 (64-bit, prefetchable) [size=256M]
        I/O ports at f000 [size=64]
        Expansion ROM at <unassigned> [disabled]
        Capabilities: [40] Vendor Specific Information: Len=0c <?>
        Capabilities: [70] Express Root Complex Integrated Endpoint, MSI 00
        Capabilities: [ac] MSI: Enable- Count=1/1 Maskable- 64bit-
        Capabilities: [d0] Power Management version 2
        Capabilities: [100] #1b
        Capabilities: [200] Address Translation Service (ATS)
        Capabilities: [300] #13

I have about 100 Dell desktops deployed with CentOS 6 all using the built-in motherboard graphics.  But on a Dell Optiplex 5050 with an Intel(R) Core(TM) i7-7700 CPU @ 3.60GHz CPU and the above graphics card, the X11 login screen is all distorted and unusable.  There is a simple solution: if I remove the "vga=0x31b” parameter from the kernel boot command it works just fine.  However, I would prefer to have a usable alternate console on our 1900x1200 monitors, but any value I tried for the vga parameter results in a distorted login screen.

Any ideas what may be causing this?  This is only an issue on the very latest chipset.  On the next most recent Dell desktops we have (Intel(R) Core(TM) i5-4590 CPU @ 3.30GHz) I do not have this issue.  Here is the VGA controller info:

00:02.0 VGA compatible controller: Intel Corporation Xeon E3-1200 v3/4th Gen Core Processor Integrated Graphics Controller (rev 06) (prog-if 00 [VGA controller])
        Subsystem: Dell Device 05a4
        Flags: bus master, fast devsel, latency 0, IRQ 28
        Memory at f7800000 (64-bit, non-prefetchable) [size=4M]
        Memory at e0000000 (64-bit, prefetchable) [size=256M]
        I/O ports at f000 [size=64]
        Expansion ROM at <unassigned> [disabled]
        Capabilities: [90] MSI: Enable+ Count=1/1 Maskable- 64bit-
        Capabilities: [d0] Power Management version 2
        Capabilities: [a4] PCI Advanced Features
        Kernel driver in use: i915
        Kernel modules: i915

Does anyone else have a similar issue and found a better solution?

Alfred